KCET Full Mock - 2
KCET Full Mock - 2
QUESTIONS
PHYSICS
a. 90 V, 2A b. 0 V, 2 A c. 90 V, 1 A d. 0 V, 1 A
3. 𝐿𝐶 oscillations are similar and analogous to the mechanical oscillations of a block attached to a
spring. The electrical equivalent of the force constant of the spring is
a. Reciprocal of capacitive reactance
b. capacitive reactance
c. Reciprocal of capacitance
d. Capacitance
4. In an oscillating 𝐿𝐶 circuit, 𝐿 = 3.00mH and 𝐶 = 2.70𝜇𝐹. At 𝑡 = 0 the charge on the capacitor is
zero and the current is 2.00 A. The maximum charge that will appear on the capacitor will be
a. 1.8 × 10−5 𝐶 b. 18 × 10−5 𝐶 c. 9 × 10−5 𝐶 d. 90 × 10−5 𝐶
5. Suppose that the electric field amplitude of electromagnetic wave is 𝐸0 = 120𝑁𝐶 −1 and its
frequency if 𝑓 = 50 𝑀𝐻𝑧. Then which of the following value incorrectly computed?
a. Magnetic field amplitude is 400 nT.
b. Angular frequency of EM wave is 𝜋 × 108 rad 𝑠 −1
c. Propagation constant (angular wave number) is 2.1 rad 𝑚−1
d. Wave length of EM wave is 6 m.
6. The source of electromagnetic wave can be a charge
a. Moving with a constant velocity
b. Moving in a circular orbit
c. At rest
d. Moving parallel to the magnetic field
7. In refraction, light waves are bend on passing from one medium to second medium becomes, in
the second medium
a. Frequency is different
b. Speed is different
c. Coefficient of elasticity is difference
d. Amplitude is smaller
8. If the refractive index from air to glass is 3/2 and that from air to water is 4/3, then the radio of
focal lengths of a glass lens in water and in air
a. 1 : 2 b. 2 : 1 c. 1 : 4 d. 4 : 1
9. Two thin biconvex lenses have focal lengths 𝑓1 and 𝑓2. A third thin biconcave lens has focal
length of 𝑓3. If the two biconvex lenses are in contact, the total power of the lenses is 𝑃1 . If the
first convex lenses is in contact with the third lens, the total power is 𝑃2 . If the second lens is in
contact with the third lens, the total power is 𝑃3 then
𝑓𝑓 𝑓𝑓 𝑓𝑓
a. 𝑃1 = 𝑓 1−𝑓2 , 𝑃2 = 𝑓 1−𝑓3 and 𝑃3 = 𝑓 2−𝑓3
1 2 3 1 3 2
𝑓1 −𝑓2 𝑓3 −𝑓1 𝑓3 −𝑓2
b. 𝑃1 = 𝑓1 𝑓2
, 𝑃2 = 𝑓3 +𝑓1
and 𝑃3 = 𝑓2 𝑓3
𝑓1 −𝑓2 𝑓3 −𝑓1 𝑓3 −𝑓2
c. 𝑃1 = 𝑓1 𝑓2
, 𝑃2 = 𝑓3 𝑓1
and 𝑃3 = 𝑓2 𝑓3
𝑓1 +𝑓2 𝑓3 −𝑓1 𝑓3 −𝑓2
d. 𝑃1 = 𝑓𝑓
, 𝑃2 = 𝑓3 𝑓1
and 𝑃3 = 𝑓2 𝑓3
1 2
10. The size of the image of an object, which is at infinity, as formed by a convex lens of focal length
30 cm is 2 cm. if a concave lens of focal length 20 cm is placed between the convex lens and the
image at a distance of 26 cm from the lens, the new size of the image is
a. 1.25 cm b. 2.5 cm c. 1.05 cm d. 2 cm
11. A slit of width 𝑎 is illuminated by red light of wavelength 6500 Å. If the first diffraction minimum
fall at 30 Å, then the value of 𝑎 is
a. 6.5 × 10−4 mm b. 1.3 micron c. 3250 Å d. 2.6 × 10−4 cm
12. Which of the statements are correct with reference to single slit diffraction patern?
(i) Fringes are of unequal width
(ii) Fringes are of equal width
(iii) Light energy is conserved
(iv) Intensities of all bright fringes are equal
a. (i) and (iii) b. (i) and (iv) c. (ii) and (iv) d. (ii) and (iii)
13. In the young’s double slit experiment a monochromatic source of wavelength 𝜆 is used. The
intensity of light passing through each slit is 𝐼0 . The intensity of light the screen 𝑆𝐶 at a point P, a
distance 𝑥 from O is given by (Take d< < D)
𝜋𝐷 𝜋𝑑 𝜋𝑑 𝜋𝑑
a. 𝐼0 cos2 (𝜆𝑑 𝑥) b. 4𝐼0 cos2 (𝜆𝐷 𝑥) c. 𝐼0 sin2 (2𝜆𝐷 𝑥) d. 4𝐼0 cos (2𝜆𝐷 𝑥)
14. The work function of a metal is 1 eV. Light of wavelength 3000 Å is incident on this metal
surface. The velocity of emitted photoelectrons will be
a. 10 𝑚𝑠 −1 b. 1 × 103 𝑚𝑠 −1 c. 1 × 104 𝑚𝑠 −1 d. 1 × 106 𝑚𝑠 −1
15. A proton moving with a momentum 𝑝1 has a kinetic energy 1/8th of its rest mass energy.
Another light photon having energy to the kinetic energy of the possesses a momentum 𝑝2 .
Then the ratio (𝑝1 − 𝑝2 )/𝑝1 is equal to
1 1 3
a. 1 b. 4 c. 2 d. 4
16. According to Einstein’s photoelectric equation to the graph between kinetic energy of
photoelectrons ejected and the frequency of incident radiation is
a. b.
c. d.
17. Energy of an electron in the second orbit of hydrogen atom is 𝐸2 . The energy of electron in the
third orbit of 𝐻𝑒 + will be
9 16 3 16
a. 𝐸
16 2
b. 𝐸
9 2
c. 16 𝐸2 d. 3 2
𝐸
18. The figure shows standing de Broglie waves due to the revolution of electron in a certain orbit of
hydrogen atom. Then the expression for the orbit radius is (all notations have their usual
meanings)
ℎ 2 𝜀0 4ℎ 2 𝜀 9ℎ 2𝜀 16ℎ2 𝜀0
a. 𝜋𝑚𝑒 2
b. 𝜋𝑚𝑒 20 c. 𝜋𝑚𝑒 20 d. 𝜋𝑚𝑒 2
19. An electron is an excited state of 𝐿𝑖 2+ion has angular momentum 3ℎ/2𝜋. The de Broglie
wavelength in this state is 𝑃𝜋𝑎0 (where 𝑎0 = Bohr radius). The value of 𝑃 is
a. 3 b. 2 c. 1 d. 4
20. Which graph in the following diagram correctly represents the potential energy of a pair of
nucleons as a function of their separation?
a. b.
c. d.
a. 80 𝑚𝑠 −1 b. 40 𝑚𝑠 −1 c. 18 𝑚𝑠 −1 d. 2 𝑚𝑠 −1
27. The maximum range of a gun on horizontal plane is 16 km. if g=10 𝑚𝑠 −2, then muzzle velocity of
a shell is
a. 160 𝑚𝑠 −1 b. 200√2𝑚𝑠 −1 c. 400 𝑚𝑠 −1 d. 800 𝑚𝑠 −1
28. The trajectory of projectile is
a. Semicircle
b. An ellipse
c. A parabola always
d. A parabola in the absence of air resistance
29. For a projectile motion, the angle between the velocity and acceleration is minimum and acute
at
a. Only one point b. two points c. three points d. four points
−1
30. A particle starts from the origin at 𝑡 = 0 𝑠 with a velocity of 10𝑗̂𝑚𝑠 and move in the 𝑥 − 𝑦
plane with a constant acceleration of (8𝑖̂ + 2𝑗̂)𝑚𝑠 −2 . At an instant when the 𝑥 − coordinate of
the particle is 16 m, 𝑦 − coordinate of the particle is:
a. 16 m b. 28 m c. 36 m d. 24 m
31. A coin placed on a rotation turn table just slips if it is placed at a distance of 4 cm from the
center. If the angular velocity of the turn table is doubled it will just slip at a distance of
a. 1 cm b. 2 cm c. 4 cm d. 8 cm
32. A 1 kg ball moving at 12 𝑚𝑠 collides with a 2 kg ball moving in opposite direction at 24 𝑚𝑠 −1 .
−1
If the coefficient of restitution is 2/3, then their velocities after the collision are
a. -4 𝑚𝑠 −1, -28 𝑚𝑠 −1 b. -28 𝑚𝑠 −1 , -4 𝑚𝑠 −1
−1 −1
c. 4 𝑚𝑠 , 28 𝑚𝑠 d. 28 𝑚𝑠 −1 , 4 𝑚𝑠 −1
33. A ball hits the floor and rebounds after an inelastic. In this case
a. The momentum of the ball is conserved
b. The mechanical energy of the ball is conserved
c. The total momentum of the ball and the earth is conserved
d. The total mechanical energy of the ball and the earth is conserved
34. In a figure 𝐸 and 𝑣𝑐𝑚 represent the total energy and speed of center of mass of an object of
mass 1 kg in pure rolling. The object is:
c. d.
38. A number of Carnot engines are operated at identical cold reservoir temperature (𝑇𝐿 ).
However, their hot reservoir temperatures are kept different. A graph of the efficiency of the
engines versus hot reservoir temperature (𝑇𝐻 ) is plotted. The correct graphical representation is
a. b.
c. d.
39. A gas mixture contains monoatomic and diatomic molecules of 2 moles each. The mixture has a
total internal energy of (symbols have usual meanings)
a. 3 RT b. 5 RT c. 8 RT d. 9 RT
40. A pendulum oscillates simple harmonically and only if
(i) The sizer of the bob of pendulum is negligible in comparison with the length of the
pendulum
(ii) The angular amplitude is less than 10°
a. Both i and ii are correct
b. Both I and ii are incorrect
c. Only I is correct
d. Only ii is correct
41. To propagate both longitudinal and transverse waves, a material must have
a. Bulk and shear moduli b. Only bulk modulus
c. Only shear modulus d. Young’s and Bulk modulus
42. A copper rod AB of length 𝑙 is rotated about end A with a constant angular velocity 𝜔. The
electric field at a distance 𝑥 from the axis of rotation is
𝑚𝜔2 𝑥 𝑚𝜔𝑥 𝑚𝑥 𝑚𝑒
a. 𝑒
b. 𝑒𝑙
c. 𝜔3 𝑙 d. 𝜔2 𝜋
43. Electric field due to infinite, straight uniformly charge wire given with distance 𝑟 as
1 1
a. 𝑟 b. 𝑟 c. 𝑟2 d. 𝑟 2
44. A 2 – gram object, located in a region of uniform electric field 𝐸⃗ = (300𝑁𝐶 −1 )𝑖̂ carries charge
𝑄. The object released from rest at 𝑥 = 0, has a kinetic energy of 0.12 J at 𝑥 = 0.5 m. Then 𝑄 is
a. 400𝜇𝐶 b. −400𝜇𝐶 c. 800𝜇𝐶 d. −800𝜇𝐶
−3
45. If a slab of insulating material (conceptual). 4 × 10 m thick is introduced between the plates
of a parallel plate capacitor, the separation between the plates has to be increased by
3.5 × 10−3 m to restore the capacity to original value. The dielectric constant of the material
will be
a. 6 b. 8 c. 10 d. 12
46. Eight drops of mercury of equal radii combine to form a big drop. The capacitance of a bigger
drop as compared to each smaller drop is
a. 2 times b. 8 times c. 4 times d. 16 times
47. Which of the statement is false in the case of polar molecules?
a. Centers of positive and negative charges are separated in the absence of external electric
field.
b. Centers of positive and negative charges are separated in the presence of external electric
field.
c. Do not possess permanent dipole moments.
d. Ionic molecule HCl is the example of polar molecule.
48. An electrician requires a capacitance of 6 𝜇𝐹 in a circuit across a potential difference of 1.5kV. A
large number of 2 𝜇𝐹 capacitors which can withstand a potential difference of not more than
500 V are available. The minimum number of capacitors required for the purpose is
a. 3 b. 9 c. 6 d. 27
49. In figure, charge on the capacitor is plotted against potential difference across the capacitor.
The capacitance and energy stored in the capacitor are respectively.
𝑥
a. 𝑥 b. 4 c. 4𝑥 d. 2𝑥
52. A copper wire of length 1 m and uniform cross sectional area 5 × 10−7 𝑚2 carries a current of 1
A. Assuming that there are 8 × 108 free electrons per 𝑚2 in copper, how long will an electron
take drift from one end of the wire to the other?
a. 0.8 × 103s b. 1.6 × 103s c. 3.2 × 103 s d. 6.4 × 103s
53. Consider an electrical conductor connected across a potential difference 𝑉. Let ∆𝑞 be a small
charge moving through it in time ∆𝑡. If 𝐼 is the electric current through it,
(i) The kinetic energy of the charge increases by 𝐼𝑉∆𝑡.
(ii) The electric potential energy of the charge decreases by 𝐼𝑉∆𝑡.
(iii) The thermal energy of the conductor increases by 𝐼𝑉∆𝑡.
c. D.
57. A tightly wound long solenoid has 𝑛 turns per unit length, a radius 𝑟 and carries a current 𝐼. A
particle having charge 𝑞 and mass 𝑚 is projected from a point on the axis in a direction
perpendicular to the axis. The maximum speed of the particle for which the particle does strike
the solenoid is
𝜇0 𝑛𝐼𝑞𝑟 𝜇0 𝑛𝐼𝑞𝑟 𝜇0 𝑛𝐼𝑞𝑟 𝜇0 𝑛𝐼𝑞𝑟
a. 𝑚
b. 2𝑚
c. 4𝑚
d. 8𝑚
58. Earth’s magnetic field always has a horizontal component except at
a. Equator b. magnetic poles c. a latitude of 60° d. an altitude of 60°
59. Which of the field pattern given below is valid for electric field as well as for magnetic field?
a. b. c. d.
60. The current following through an inductance coil self-inductance 6 mH at different time instant
is as shown. The emf induced between 𝑡 = 20𝑠 and 𝑡 = 40 𝑠 is nearly
CHEMISTRY
1. Zeta potential is
a. Potential required to bring about coagulation of a colloidal sol
b. Potential required to give the particle a speed of 1 cm s-1
c. Potential difference between fixed charged layer and the diffused layer having opposite
charges.
d. Potential energy of the colloidal particles
2. Which of the following compound on heating given N2O?
a. Pb(NO3)2 b. NH4NO3 c. NH4NO2 d. NaNO3
3. Which of the following property is true for the given sequence
NH3 > PH3 > AsH3 > SbH3 > BiH3
a. Reducing property b. Thermal stability c. Bond angle d. Acidic character
4. The correct order of boiling point in the following compound is
a. HF > H2 O > NH3 b. H2 O > HF > NH3
c. NH3 > H2 O > HF d. NH3 > HF > H2 O
5. XeF6 on partial hydrolysis give a compound X, which has square pyramidal geometry. The ‘X’ is
a. XeO3 b. XeO4 c. XeOF4 d. XeO2 F2
6. A colourless, neutral paramagnetic oxide of nitrogen ‘P’ on oxidation gives reddish brown gas Q.
Q on cooling gives colourless gas R, R on reaction with P gives blue solid S. Identify P, Q, R, S,
respectively.
a. N2 O NO NO2 N2 O3 b. N2 O NO2 N2 O4 N2 O3
b. NO NO2 N2 O4 N2 O3 d. NO NO2 N2 O4 N2 O5
7. Which of the following does not represent property stated against it?
a. CO2+ < Fe2+ < Mn2+ − Ionic size
b. Ti < V < Mn − Number of oxidation states
2+ 2+ 2+
c. Cr < Mn < Fe − Paramagnetic behaviour
d. Sc > Cr > Fe − Density
8. Which one of the following is correct for all elements form Sc to Cu?
a. The lowest oxidation state shown by them is +2.
b. 4s orbital is completely filled in the ground state
c. 3d orbital is not completely filled in the ground state.
d. The ions in +2 oxidation states are paramagnetic
9. When the absolute temperature of ideal gas is doubled and pressure is halved, the volume of
gas
a. Will be half of original volume b. will be 4 times the original volume
c. Will be 2 times the original volume d. will be ¼ times the original volume
10. Which of the following pairs has both the ions coloured in aqueous solution? [Atomic numbers
of Sc = 21, Ti = 22, Ni = 28, Cu = 29, Mn = 25]
a. Sc 3+ Mn2+ b. Ni2+ , Ti4 c. Ti3+ , Cu+ d. Mn2+ , Ti3+
11. For the crystal field splitting in octahedral complexes,
3
a. The energy of the eg orbitals will decrease by (5) ∆0 and that of the t 2g will increase by (2/5)
∆o .
3
b. The energy of the eg orbitals will increase by (5) ∆0 and that of the t 2g will decrease by (2/5)
∆o
3
c. The energy of the eg orbitals will increase by ( ) ∆0 and that of the t 2g will increase by (2/5)
5
∆o
3
d. The energy of the eg orbitals will decrease by ( ) ∆0 and that of the t 2g will decrease by
5
(2/5) ∆o
12. Peroxide effect is observed with the addition of HBr but not with the addition of HI to
unsymmetrical alkene because
a. H − I bond is strong that H − Br and is not cleaved by the free radical.
b. H − I bond is weaker than H − Br bond so that iodine free radicals combine to form iodine
molecules.
c. Bond strength of HI and HBr are same but free radicals are formed in HBr
d. All of these.
13. The IUPAC name of [Co(NH3 )5 (CO3 )]Cl is
a. Pentaamminecarbonatocobalt (III) Chloride
b. Carbonatopentamminecobalt (III) Chloride
c. Pentaamminecarbonatocobaltate (III) Chloride
d. Pentaammine cobalt (III) Carbonate Chloride
14. Homoleptic complexes among the following are
i. K 3 [Al(C2 O4 )]3 ii. [CoCl2 (en)2 ]+ iii. K 2 [Zn(OH)4 ]
a. (i) only b. (i) and (ii) only c. (i) and (iii) only d. (iii) only
15. The correct order for wavelength of light absorbed in the complex ions
[CoCl(NH3 )5 ]2+ , [Co(NH3 )6 ]3+ and [Co(CN)6 ]3− is
a. [CoCl(NH3 )5 ]2+ > [Co(NH3 )6 ]3+ > [Co(CN)6 ]3−
b. [Co(NH3 )6 ]3+ > [Co(CN)6 ]3− > [CoCl(NH3 )5 ]2+
c. [Co(CN)6 ]3− > [CoCl(NH3 )5 ]2+ > [Co(CN)6 ]3−
d. [Co(NH3 )6 ]3+ > [CoCl(NH3 )5 ] > [Co(CN)6 ]3−
16.
b.
c.
d.
17. Bond enthalpies of A2 , B2 and AB are in the ratio 2: 1: 2. If bond enthalpy of formation of AB is
−100 kJ mol− . The bond enthalpy of B2 is
a. 100 kJ mol−1 b. 50 kJ mol−1 c. 200 kJ mol−1 d. 150 kJ mol−1
18. The order of reactivity of the compounds
C6 H5 CH2 Br, C6 H5 CH(C6 H5 )Br, C6 H5 CH(CH3 )Br and C6 H5 C(CH3 )(C6 H5 )Br in SN 2 reaction is
a. CH3 H H H
| | | |
C6 H5 − C − Br < C6 H5 − C − Br < C6 H5 − C − Br < C6 H5 − C − Br
| | | |
C6 H5 C6 H5 CH3 H
b. H H H CH3
| | | |
C6 H5 − C − Br < C6 H5 − C − Br < C6 H5 − C − Br < C6 H5 − C − Br
| | | |
H CH3 C6 H5 C 6 H5
c. H H H CH3
| | | |
C6 H5 − C − Br < C6 H5 − C − Br < C6 H5 − C − Br < C6 H5 − C − Br
| | | |
CH3 H C6 H5 C 6 H5
d. H H H CH3
| | | |
C6 H5 − C − Br < C6 H5 − C − Br < C6 H5 − C − Br < C6 H5 − C − Br
| | | |
C6 H5 H CH3 C 6 H5
HBr
19. The major product of the following reaction is CH2 = CH − CH2 − OH →
product
Excess
a. CH3 − CHBr − CH2 Br b. CH2 = CH − CH2 Br
c. CH3 − CHBr − CH2 − OH d. CH3 − CHOH − CH2 OH
20.
The product ‘A’ gives white precipitate when treated with bromine water. The product ‘B’ is
treated with Barium hydroxide to give the product C. The compound C is heated strongly to
form product D. The product D is
a. 4 − methylpent − 3 − en − 2 − one b. but − 2 − enal
c. 3 − methylpent − 3 − en − 2 − one d. 2 − methylbut − 2 − enal
21. For the reaction A(g) + B(g) ⇌ C(g) + D(g); ∆H = −Q kJ
The equilibrium constant cannot be disturbed by
a. Addition of A b. Addition of D
c. Increasing of pressure d. Increasing of temperature
22. An organic compound ‘X’ on treatment with PCC in dichloromethane gives the compound Y.
Compound ‘Y’ reacts with I2 and alkali to form yellow precipitate of triiodomethane. The
compound X is
a. CH3 CHO b. CH3 COCH3 c. CH3 CH2 OH d. CH3 COOH
23. A compound ‘A’ (C7 H8 O) is insoluble in NaHCO3 solution but dissolve in NaOH and gives a
characteristics colour with neutral Fecl3 solution. When treated with Bromine water compound
‘A’ forms the compound B with the formula C7 H5 OBr3 . ‘A’ is
a. b.
c. d.
25. K a values for acids H2 SO3 , HNO2 , CH3 COOH and HCN are respectively 1.3 × 10−2 , 4 ×
10−4 , 1.8 × 10−5 and 4 × 10−10 , which of the above acids produces stronger conjugate base in
aqueous solution?
a. H2 SO3 b. HNO2 c. CH3 COOH d. HCN
26.
a. P > S > R > Q b. S > R > Q > P c. Q > R > S > P d. P > Q > R > S
49. The number of angular and radial nodes in 3p orbital respectively are
a. 3, 1 b. 1, 1 c. 2, 1 d. 2,3
50. The resistance of 0.01 m KCl solution at 298 K is 1500 Ω. If the conductivity of 0.01 m KCl
solution at 298 K is 0.146 × 10−3 S cm−1 . The cell constant of the conductivity cell in cm−1 is
a. 0.219 b. 0.291 c. 0.301 d. 0.194
51. H2 (g) + 2 AgCl(s) ⇌ 2 Ag(s) + 2HCl(aq)
0
Ecell at 25°C for the cell is 0.22 V. The equilibrium constant at 25°C is
a. 2.8 × 107 b. 5.2 × 108 c. 2.8 × 105 d. 5.2 × 104
52. For a reaction A + 2B → Products, when concentration of B alone is increased half-life remains
the same. If concentration of A alone is doubled, rate remains the same. The unit of rate
constant for the reaction is
a. s −1 b. L mol−1 s −1 c. mol L−1 s −1 d. atm−1
53. The third ionisation enthalpy is highest in
a. Alkali metals b. alkaline earth metals
c. Chalcogens d. pnictogens
54. If the rate constant for a first-order reaction is k, the time (t) required for the completion of 99%
of the reaction is given by
4.606 2.303 0.693 6.909
a. t = k
b. t = k
c. t = k
d. t = k
55. The rate of a gaseous reaction is given by the expression k[A][B]2 . If the volume of vessel is
reduced to one half of the initial volume, the reaction rate as compared to original rate is
1 1
a. 16
b. 8 c. 8 d. 16
56. The correct IUPAC name of
MATHEMATICS
a. 5𝑥 + 4𝑦 ≥ 20, 𝑥 ≤ 6, 𝑦 ≥ 3, 𝑥 ≥ 0, 𝑦 ≥ 0
b. 5𝑥 + 4𝑦 ≤ 20, 𝑥 ≤ 6, 𝑦 ≤ 3, 𝑥 ≥ 0, 𝑦 ≥ 0
c. 5𝑥 + 4𝑦 ≥ 20, 𝑥 ≤ 6, 𝑦 ≤ 3, 𝑥 ≥ 0, 𝑦 ≥ 0
d. 5𝑥 + 4𝑦 ≥ 20, 𝑥 ≥ 6, 𝑦 ≤ 3, 𝑥 ≥ 0, 𝑦 ≥ 0
3 1
21. Given that A and B are two events such that 𝑃(𝐵) = 5 , 𝑃(𝐴/𝐵) = 2 and 𝑃(𝐴 ∪ 𝐵) =
4
5
𝑡ℎ𝑒𝑛 𝑃(𝐴) =
3 1 1 3
a. 10
b. 2 c. 5 d. 5
22. If A, B and C are three independent events such that 𝑃(𝐴) = 𝑃(𝐵) = 𝑃(𝐶) = 𝑃 then 𝑃 ( at least
two of A, B, C occur)=
a. 𝑃3 − 3𝑃 b. 3𝑃 − 2𝑃2 c. 3𝑃2 − 2𝑃3 d. 3𝑃2
23. Two dice are thrown. If it is known that the sum of numbers on the dice was less than 6 the
probability of getting a sum as 3 is
1 5 1 2
a. 18
b. 18 c. 5 d. 5
24. A car manufacturing factor has two plants X and Y. plant X manufactures 70% of cars and plant Y
manufactures 30% of cars. 80% of cars at plant X and 90% of cars at plant Y are rated as
standard quality. A car is chosen at random and is found to be of standard quality. The
probability that it has come from plant X is
56 56 56 56
a. 73
b. 84 c. 83 d. 79
25. In a certain town 65% families own cellphones, 15000 families own scooter and 15% families
own both. Taking into consideration that the families own at least one of the two, the total
number of families in the town is
a. 20000 b. 30000 c. 40000 d. 50000
26. A and B are non-singleton sets and 𝑛(𝐴 × 𝐵) = 35. If 𝐵 ⊂ 𝐴 then 𝑛(𝐴)𝐶𝑛(𝐵) =
a. 28 b. 35 c. 42 d. 21
𝑥
27. Domain of 𝑓(𝑥) = 1−|𝑥|
is
a. 𝑅 − [−1, 1] b. (−∞, 1) c. (−∞, 1) ∪ (0, 1) d. 𝑅 − {−1, 1}
28. The value of cos 1200° + tan 1485° is
1 3 3 1
a. 2
b. 2 c. − 2 d. − 2
29. The value of tan 1° tan 2° tan 3° … … … … tan 89° is
1
a. 0 b. 1 c. d. -1
2
1+𝑖 𝑥
30. If (1−𝑖) = 1 then
a. 𝑥 = 4𝑛 + 1; 𝑛 ∈ 𝑁 b. 𝑥 = 2𝑛 + 1; 𝑛 ∈ 𝑁
c. 𝑥 = 2𝑛; 𝑛 ∈ 𝑁 d. 𝑥 = 4𝑛; 𝑛 ∈ 𝑁
31. The cost of revenue functions of a product are given by 𝐶(𝑥) = 20𝑥 + 4000 and 𝑅(𝑥) = 60𝑥 +
2000 respectively where 𝑥 the number of items is produced and sold. The value of 𝑥 to earn
Profit is
a. > 50 b. > 60 c. > 80 d. > 40
32. A student has to answer 10 questions, choosing at least 4 from each of the parts A and B. if
there are 6 questions in part A and 7 in part B, then the number of ways can the student choose
10 questions is
a. 256 b. 352 c. 266 d. 426
33. If the middle term of the A.P is 300 than the sum of its first 51 terms is
a. 15300 b. 14800 c. 16500 d. 14300
34. The equation of straight line which passes through the point (𝑎 cos 𝜃 , 𝑎 sin3 𝜃) and
3
Biology
a. (a) – (iv); (b) – (iii); (c) – (ii); (d) – (i) b. (a) – (iii); (b) – (iv); (c) – (i); (d) – (ii)
b. (a) – (iv); (b) – (iii); (c) – (i); (d) – (ii) d. (a) – (iii); (b) – (iv); (c) – (ii); (d) – (i)
18. The correct sequence of events in prophase I is
a. Synapsis → Crossing over → Chiasmata → Terminalisation
b. Crossing over→ Synapsis Chiasmata→ Terminalisation
c. Chiasmata → Synapsis → Crossing over → Terminalisation.
d. Chiasmata → Crossing over → Synapsis → Terminalisation.
19. The enzyme that is not found is C, plants is
a. ATP synthase b. RUBP carboxylase
c. NADP reductase d. PEP carboxylase
20. Match the location of the cell given in Column I with its function in Column II.
Column I Column II
(a) Mitochondrial matrix (i) Krebs cycle
(b) Cytoplasm (ii) ETC
(c) 𝐹0 and 𝐹1 (iii) Glycolysis
(d) Inner mitochondrial membrane (iv) ATP synthesis
a. (a)-(i); (b)-(iii); (c) - (iv); (a)-(ii) b. (a)-(ii); (b)-(iv); (c)-(ii); (d) - (iii)
c. (a)-(iii); (b)(ii); (c)-(i); (d)-(iv) d. (a)-(iv); (b)-(i); (c)-(iii); (d)-(ii)
21. Identify the incorrect statement/s.
I. Kinetin is a derivative of Adenine which is a pyrimidine.
II. The technique of decapitation is widely used in tea plantations.
III. Ethylene is a gaseous plant hormone.
IV. Use of G𝐴3 hastens the malting process in brewing industry.
V. ABA is a growth promoter.
a. I. II, III, IV b. Only III c. II, III, IV d. I and IV
22. Calculate the cardiac output of an individual having 70 heart beats/min with a stroke volume of
55 ml.
a. 3750 ml b. 125 ml c. 3850 ml d. None of the above
23. In a standard ECG, one of the following functions of its compo nents is not correctly interpreted.
a. P is the contraction of only left atria
b. QRS complex represents ventrical contraction.
c. T is the end of systole
d. P is the contraction of both atria.
24. Match the hormones of Column I with its functions in Column II.
Column I Column II
(a) Catecholamines (i) Diurnal rhythm
(b) MSH (ii) Immune response
(c) Thymosins (iii) Pigmentation
(d) Melatonin (iv) Stress hormone
a. (a)-(iv); (b)-(iii); (c) - (ii); (d) - (i) b. (a)-(iii); (b)-(ii); (c) – (iv); (d) – (i)
c. (a)-(ii); (b)-(iv); (c) – (iii); (d) – (i) d. (a)-(i); (b)(ii); (c) – (iii); (d) – (iv)
25. How many microsporangia are located at the corners of a typi- cal bilobed anther of
angiosperm?
a. 2 b. 4 3. 8 d. 1
26. In Bryophytes and Pteridophytes the number of male gametes produced is several thousand
times the number of female gametes produced.
Reason: Large number of male gametes fail to reach the female gametes during transport.
a. Assertion is correct but reason in incorrect.
b. Both Assertion and reason are correct.
c. Assertion is incorrect, but reason is correct.
d. Both Assertion and reason are incorrect.
27. In the given diagram identify the parts labelled as a, b, c and d.
a. a→ Coleoptile, b→ Scutellum, c→ Pericarp, d→ Coleorhiza
b. a → Coleoptile, b→ Scutellum, c→ Coleorhiza, d→ Pericarp
c. a→ Pericarp, b→ Coleorhiza, e→ Scutellum, d → Coleoptile
d. a→ Coleorhiza. b→ Coleoptile, c→ Scutellum, d→ Pericarp
28. Consider the following statements and choose the correct answer from the given options.
Statement 1: Innermost layer of microsporangium is tapetum.
Statement 2: Cells of tapetum possess dense cytoplasm more than one nucleus and nourishes
developing pollen grains.
a. Both Statements 1 and 2 are incorrect.
b. Both Statements 1 and 2 are correct.
c. Statement I is correct and 2 is incorrect.
d. Statement 2 is correct and I is incorrect.
29. Identify the correct statement.
a. Only one megaspore present towards chalazal end remains functional.
b. 3 megaspores present towards chalazal end degenerate gradually.
c. Each megaspore mother cell directly develops into a megaspore.
d. Each female gametophyte is 7-celled and 7-nucleated structure.
30. Which of the following aquatic plant does not show pollination by water?
a. Vallisneria b. Hydrilla c. Water hyacinth d. Zostera
31. Which cell of the female gametophyte is involved in the forma- tion of primary endosperm
nucleus (PEN) after fertilization?
a. Antipodals b. Synergids c. Egg cell d.Central Cell
32. In the given diagram of human sperm, identify the functions of the labelled parts. a, b and c.
a. a→ Heipe u petietration of sperm into ovum.
b→ Helps in movement of sperm
c→ Provides energy for the movement of sperms into the female reproductive tract.
b. a→ Helps in penetration of sperm into ovum.
b→ Provides energy for the movement of sperm.
c→ Helps in movement of sperm.
c. a→ Helps in movement of sperm.
b→ Helps in penetration of sperm into ovum.
c→ Provides energy for the movement of sperms.
d. a→ Provides energy for the movement of sperm.
b→ Helps in movement of sperm.
c→Helps in penetration of sperm into ovum.
33. Select the correct path of flow of milk during breast feeding.
a. Mammary tubules Mammary duct → Mammary ampulla→ Lactiferous duct→ Alveoli
b. Mammary tubules → Mammary duct → Lactiferous duct→Mammary ampulla → Alveoli
c. Alveoli →Mammary tubules →Mammary ampulla →Mammary duct → Lactiferous duct
d. Alveoli Mammary tubules → Mammary duct → Mammary ampulla→ Lactiferous duct
34. Under the influence of oxytocin which layer of the uterus exhibits strong contractions during
parturition?
a. Endometrium b. Myometrium c. Perimetrium d. Both (1) and (3)
35. Select the incorrect statement about contraceptives.
a. They are regular requirements for the maintenance of reproductive health
b. They have a significant role in checking uncontrolled growth of population
c. They are practised against a natural reproductive events like conception or pregnancy The
possible ill-effects like nausea, abdominal pain,
d. irregular menstrual bleeding or even breast cancer should not be totally ignored
36. The method of directly injecting a sperm into ovum is called
a. GIFT b. ZIFT c. ICSI. d. IVF-ET
37. Match Column I with Column II and find the correct answer.
Column I Column II
(a) Aneuploidy (i) Increase in whole set of chromo- somes
(b) Monoploidy (ii) Loss or gain of a chromosome
(c) Polyploidy (iii) Two sets of chromosomes
(d) Diploidy (iv) A single set of chromosomes
a. (a)-(i); (b)-(ii); (c)-(iii); (d) - (iv) b. (a)-(iii); (b)- (i); (c)- (ii); (d)-(iv)
c. (a) –(ii); (b)-(iv); (c)-(i);(d)-(iii) d. (a)-(iv); (b) (iii); (c)-(i), (d)-(ii)
38. The genotype of a husband and wife are 𝐼 𝐴 𝐼 𝐵 and 𝐼 𝐴 𝐼 0 Among the blood types of their children,
A - B how many different genotypes and phenotypes are passible?
a. 3 genotypes; 3 phenotypes
b. 4 genotypes, 3 phenotypes
c. 4 phenotypes; 3 genotypes
d. 4 phenotypes; 4 genotypes
39. What is the possible blood group of children whose parents are heterozygous for A and B blood
groups?
a. A. B only b. A. B. A B and O
c. AB only d. A. B and AB only
40. Match the Column I with Column II.
Column I Column II
(a) Autosomal trisomy (i) Turner's Syndrome
(b) Allosomal trisomy (ii) Mendelian disorder
(c) Allosomal Monosomy (iii) Klinefelter's Syndrome
(d) Cystic fibrosis (iv) Down's. Syndrome
a. (a) – (i); (b) - (ii); (c) – (iii) ; (d) – (iv) b. (a) – (i); (b) (iv); (c) – (ii) ; (d) – (iii)
b. (a) – (iii); (b) (i); (c) – (iv) ; (d) – (ii) d. (a) – (iii); (b) (ii); (c) – (i) ; (d) – (iv)
43. In which region of the t-RNA molecule is the amino-acid binding site located?
a. 5' end b. anticodon loop c. 3' end d. None of the above
15 14
44. E. Coli fully labelled 𝑁 with is allowed to grow in 𝑁 medium The two strands of DNA
molecule of the first-generation bacteria have
a. same density and resemble with their parent DNA.
b. same density but do not resemble with their parent DNA
c. different density but do not reseple with their parent DNA
d. different density but resemble with their parent DNA
45. Experiments involving use of radioactive thymidine to detect distribution of newly synthesized
DNA in the chromosome was performed us which plant?
a. Vicia faba b. Pisum sativum
c. Coccus nucifera Antirrhinum
46. If the sequend of nucleotides in a templates stand of DNA is 3’-ATGCTTCCGGAAT-5’. Write the
sequence in the coresponding region of the transcribed m-RNA.
a. 5’-TAC GAA GGC CTT-3′ b. 5’-UAC GAA GGC UUA-3'
b. 3’-UAC GAA GGC UUA-5' d. 3’-TACGAA GGC CTT-5
47. Pneumonia is caused by
a.Streptococcus pneumonia. b. Haemophilus influenzae.
c. Both (1) and (2) d. None
48. The development of quick immune response in a person infected with deadly microbes by
administering preformed anti- bodies is
a. active immunity. b. cell-mediated immunity.
c. innate immunity. d. passive immunization.
49. Which is the most feared property of malignant tumor?
a. Neoplasty b. Metastasis
b. Rapid invasive growth d. Loss of contact inhibition
50. Identify the techniques useful in detecting the cancers of internal organs.
a. CT b. MRI c. Radiography d. All of the above
51. Which among the following plants is a source of drug which is native to America?
a. Papaver Somniferum b. Erythroxylum coca
b. Cannabis sativa d. Atropa belladonna
52. The technology of biogas production was developed in India due to the efforts of
a. KVIC b. IARI c. CDRI d. Both (1) and (2)
53. Which among the following products of microbes is not obtained from fungi?
a. Penicillin b. Statins c. Swiss cheese d. Cyclosporin - A
54. Match the following.
Column I Column II
(a) Cyclosporin-A (i) Clot busters
(b) Streptokinase (ii) Antibiotic
(c) Statins (iii) Immuno suppressive agent
(d) Penicillin (iv) Blood cholesterol lowering agent
EXPLENATIONS
PHYSICS
1. (D) : work energy and power
Self-inductance and mutual inductance have same unit both measure magnetic flux
per unit current. The magnetic flux ha unit 𝑊𝑏.
𝜙 𝑊𝑏
𝐿=𝑀= =
𝐴 𝐴
2. (b) :
This is a 𝑅𝐿𝐶 circuit, the total impedance is calculated as,
𝑍 = √𝑅 2 + (𝑋𝐿 − 𝑋𝐶 )2
= √(45Ω)2 − (4Ω − 4Ω)2 = 45Ω
The current in the circuit is expressed as,
𝐸 90𝑉
𝐼= = = 2𝐴
𝑍 45Ω
The current is 2 A.
The potential is calculated as,
𝑉 = (𝑋𝐿 − 𝑋𝐶 )𝐼
= (4Ω − 4Ω) − 2𝐴 = 0𝑉
𝑡ℎ𝑒 𝑝𝑜𝑡𝑒𝑛𝑡𝑖𝑎𝑙 𝑖𝑠 0 𝑉.
3. (c) :
At resonance the 𝐿𝐶 circuit is expressed as,
𝑑2 𝐼 𝑙
𝐿 2+ 𝐼=0
𝑑𝑡 𝐶
The spring block system is expressed as,
𝑑2 𝑥
𝑚 2 + 𝑘𝑥 = 0
𝑑𝑥
Comparing both equations, we get
1
𝑚 ∝ 𝐿, 𝑘 ∝
𝐶
4. (b) ;
The change as a function of time is expressed as,
𝑞 = 𝑄 sin 𝜔𝑡
Here, Q is the maximum charge on the capacitor and 𝜔 is the angular frequency of
oscillation.
At time 𝑡 = 0, the charge is 𝑞 = 0.
We know that current is expressed as,
𝑑𝑞 𝑑(𝑄 sin 𝜔𝑡)
𝐼= = = 𝜔𝑄 cos 𝜔𝑡
𝑑𝑡 𝑑𝑡
So, substituting 𝑡 = 0,
𝐼0 = 𝜔𝑄 cos(0) = 𝜔𝑄
𝐼0
⇒ 𝑄 = 𝐼0 √𝐿𝐶
𝜔
= (2𝐴)√(3 × 10−3 𝐻)(2.70 × 10−6 𝐹)
= 1.8 × 10−4 𝐶 = 18 × 10−5 𝐶
5. (c) :
The magnetic field amplitude is expressed as,
𝐸0 120𝑁/𝐶
𝐵0 = = = 400𝑛𝑇
𝑐 3 × 108 𝑚/𝑠
The angular frequency is expressed as,
𝜔 = 2𝜋𝑓 = 2𝜋(50𝑀𝐻𝑧) = 3.14 × 108 𝑟𝑎𝑑𝑠 −1 = 𝜋 × 108 𝑟𝑎𝑑𝑠 −1
The propagation constant is expressed as,
𝜔
𝑘 = = 1.05𝑟𝑎𝑑𝑚−1
𝑐
The wavelength is given as,
𝑐
𝜆 = = 6𝑚
𝑓
6. (b) :
Motion of a particle in circular orbit is accelerated motion, thus source of
electromagnetic wave can be a charge moving in the circular orbit.
7. (b) :
When a light wave passes from one medium to other, Refractive index charges due to
which its velocity and wave-length charges.
𝑐 𝑐
𝑛= ⇒𝑣=
𝑣 𝑛
𝑐
𝜆 = 𝑣𝑓 =
𝑛
So, charge in light wave velocity and wavelength, wave bents.
8. (d) :
The refractive index from air to glass is,
3
𝑎𝜇𝑔 =
2
The refractive index from air to water is,
4
𝑎𝜇𝑔 =
3
The refractive index from water to glass is,
𝑎𝜇𝑔 3/2 9
𝑤𝜇𝑔 = = =
𝑎𝜇𝑤 4/3 8
The expression for the focal length for water glass medium is,
1 1 1
= (𝑤𝜇𝑔 − 1) ( − )
𝑓𝑤 𝑅1 𝑅2
The expression for the focal length for air, in air-glass medium is
1 1 1
= (𝑎𝜇𝑔 − 1) ( − )
𝑓𝑎 𝑅1 𝑅2
the required ratio is,
𝑓𝑤 (𝑎𝜇𝑔 − 1) 3/2 − 1 4
= = =
𝑓𝑎 (𝑤 − 1) 9/8 − 1 1
𝜇𝑔
9. (d) :
There are three arrangements of the thin biconvex lens. For the first case, two biconvex
lenses the power of the combination is,
1 1 𝑓1 + 𝑓2
𝑃1 = + =
𝑓1 𝑓2 𝑓1 𝑓2
For the second case, first biconvex lens is in contact with the third biconcave lens, the
power of the combination is,
1 1 𝑓3 − 𝑓1
𝑃2 = + =
𝑓1 𝑓3 𝑓1 𝑓3
for the third case, second biconvex lens is in contact with the third biconcave lens, the
power of combination is,
1 1 𝑓3 − 𝑓2
𝑃3 = + =
𝑓2 𝑓3 𝑓3 𝑓2
10. (b) :
The lens formula is,
1 1 1
= −
𝑓 𝑣 𝑢
1 1 1
⇒ = −
−20𝑐𝑚 𝑣 4𝑐𝑚
⇒ 𝑣 = 5𝑐𝑚
The magnification is given as,
𝑣 5
𝑚= = = 1.25
𝑢 4
The new size of the image is,
ℎ𝑖′
= 1.25
ℎ𝑖′
ℎ𝑖′ = (1.25)(2𝑐𝑚) = 2.5𝑐𝑚
11. (b) :
The principle of diffraction says,
𝑎 sin 𝜃 = 𝑛𝜆
Where 𝑎 is slit width, 𝑛 is order of secondary maxima, and 𝜆 is wavelength.
Given that, 𝜃 = 30°, 𝑛 = 1 and 𝜆 = 650𝑛𝑚. Then, 𝑎 sin 30° = 1(6500 × 10−10 𝑚)
(6500×10−10 𝑚)
⇒𝑎= = 1.3 × 10−10 𝑚 = 1.3𝜇𝑚 = 1.3 micron
sin 30°
12. (a) :
The single slit diffraction pattern is observed when a coherent light is passed through
one slit and the slit size is comparable to wavelength of light. Intensity of the central
fringe is maximum and then it decreases. The fringe pattern is of unequal width and
unequal intensity. The light energy is conserved in ideal case as there is no loss due to
heat or other medium issues.
13. (b):
The expression for the resultant intensity is,
∆𝜙
𝐼𝑅 = 4𝐼0 cos2 ( )
2
Path difference is given by,
𝑥
∆𝑥 = 𝑑
𝐷
The phase difference is given by,
2𝜋∆𝑥
∆𝜙 =
𝜆
𝜙 𝜋∆𝑥 𝑥
= = 𝜋𝑑
2 𝜆 𝜆𝐷
The resultant intensity will be,
𝑥
𝐼𝑅 = 4𝐼0 cos2 (𝜋𝑑 )
𝜆𝐷
14. (d) :
The Einstein photoelectric equation is expressed as,
𝐸 = work function +𝐾𝑚𝑎𝑥
⇒ ℎ𝑓 = 𝜙 + 𝐾𝑚𝑎𝑥
ℎ𝑐 1 2
⇒ = 𝜙 + 𝑚𝑣𝑚𝑎𝑥
𝜆 2
Substitute the given value, we have
(6.6 × 10−34 𝐽 ∙ 𝑠)(3 × 108 𝑚/𝑠) 1
−10
= (1 × 1.6 × 10−19 𝐽) + (9.1 × 10−31 𝑘𝑔)𝑣 2
(3000 × 10 𝑚) 2
6
⇒ 𝑣 = 1 × 10 𝑚/𝑠
15. (d):
Given that, the kinetic energy of proton is 1/8th of its rest mass energy. That is,
𝑝12 1
𝐾= = 𝑚𝑐 2
2𝑚 8
2 𝑚𝑐
⇒ 𝑝1 = √ 𝑚2 𝑐 2 =
8 2
For second case, we have the kinetic energy of photon is equal to its rest mass energy.
That is,
𝐾 = 𝑝2 𝑐 − 𝑚𝑐 2 = 𝑚𝑐 2
⇒ 𝑝2 𝑐 = 2 𝑚𝑐 2 ⇒ 𝑝2 = 2𝑚𝑐
𝑝 −𝑝
Therefore, the ratio will be 1𝑝 2,
2
𝑝1 − 𝑝2 (𝑚𝑐/2) − 2𝑚𝑐 3
= =
𝑝1 𝑚𝑐/2 4
16. (d) :
The Einstein photoelectric equation is expressed as,
𝐸 =work function +𝐾𝑚𝑎𝑥
⇒ ℎ𝑓 = 𝜙 + 𝐾𝑚𝑎𝑥
⇒ 𝐾𝑚𝑎𝑥 = −𝜙 + ℎ𝑓
The final equation resembles,
𝑦 = 𝑚𝑥 + 𝑐
Here, 𝑦 = 𝐾𝑚𝑎𝑥 , 𝑚 = ℎ, 𝑥 = 𝑓 and 𝐶 = −𝜙.
So, the correct graph between kinetic energy and frequency is
17. (b) :
The energy of an electron in the orbit of the atom is expressed as,
𝑘𝑍 2
𝐸𝑛 = 2
𝑛
Here, 𝑍 iz atomic number, 𝑛 is the orbit in which electron is present, and 𝑘 is constant.
So, the energy of second orbit of hydrogen atom is,
𝑘(1)2 𝑘
𝐸1 = 𝐸 = =
22 4
Energy of electron in third orbit of 𝐻𝑒 + is,
𝑘(2)2 4𝑘 𝑘 16 16 16𝐸
𝐸3 = 2
= = ( ) = 𝐸( )=
3 9 4 9 9 9
18. (*):
According to Bohr’s second postulate,
𝑛ℎ
𝑚𝑣𝑟 = 2𝜋 (1)
Where 𝑚 be the mass of an electron, 𝑣 be the velocity and 𝑟 be the radius of orbit in
which the electron revolves around the nucleus.
The velocity of an electron is expressed as,
𝑛ℎ
𝑣= (2)
2𝜋𝑚𝑟
Here, the centripetal force is provided by the electrostatic force of attraction between
electron and nucleus.
𝑚𝑣 2 1 𝑒2
=
𝑟 4𝜋𝜀0 𝑟 2
1 𝑒2
⇒ 𝑟 = 4𝜋𝜀 2 (3)
0 𝑚𝑣
From Eqs. (2) and (3), we get
1 𝑒2 4𝜋 2 𝑚2 𝑟 2 𝑒 2
𝑟= =
4𝜋𝜀0 𝑛ℎ 2 4𝜋𝜀0 𝑚𝑛2 ℎ2
𝑚 (2𝜋𝑚𝑟)
𝜀0 𝑛2 ℎ2
⇒𝑟=
𝜋𝑚𝑒 2
19. (b) :
The angular momentum is expressed as,
𝑛ℎ
𝐿=
2𝜋
For 𝑛 = 3, we have
3ℎ
𝐿=
2𝜋
The wavelength is expressed as,
ℎ ℎ ℎ𝑟
𝜆= = =
𝑝 𝑚𝑣 𝑚𝑣𝑟
The velocity of an electron is expressed as,
𝑛ℎ
𝑣=
2𝜋𝑚𝑟
For 𝑛 = 3, we have
3ℎ
𝑣=
2𝜋𝑚𝑟
ℎ𝑟 ℎ𝑟 2𝜋𝑟
So,𝜆 = 3ℎ = 3ℎ/2𝜋 = 3
𝑚𝑟( )
2𝜋𝑚𝑟
The radius is expressed as,
𝑎0 𝑛2
𝑟=
𝑍
Substitute the value in wavelength equation,
2𝜋 𝑎0 𝑛2
𝜆= ( )
3 𝑍
For 𝑛 = 3 and Z=3, we have
2𝜋 𝑎0 (3)2
𝜆= ( ) = 2𝜋𝑎0
3 3
Comparing from the given equation,
𝑃𝜋𝑎0 = 2𝜋𝑎0
𝑃=2
20. (d):
The potential energy of the two nucleon is in the order of MeV. Thus, the graph in
options (A) and (D) are two possible options. Nuclear force is of attractive nature when
the separation is greater than 1 fm and repulsive if less than 1 fm. So, the option (A) is
not possible because point of stable equilibrium will be negative not positive.
21. (b) :
For elastic collision masses of both must be equal so that they can exchange the
velocities. To slow down the speed of neutron substance should be made up of 1 proton
for perfectly elastic, that is, we need light nuclei not heavy. In heavy nuclei only
direction will change not the speed.
22. (b) :
The given figure can redraw as following figure
38. (b) :
The efficiency of Carnot engine working between two temperature is expressed as,
𝑇𝐿 𝑇𝐻 − 𝑇𝐿
𝜂 =1− =
𝑇𝐻 𝑇𝐻
Carnot engine will not work if (𝑇𝐻 < 𝑇𝐿 ).
At, (𝑇𝐻 < 𝑇𝐿 ), the efficiency 𝜂 will be zero.
From this point the increasing 𝑇𝐻 will only increase 𝜂.
The only graph representing such movement is,
39. (c) :
The value of degree of freedom (𝑓) for monoatomic and diatomic gases are 3 and 5,
respectively.
The charge in internal energy for the mixture is,
𝑓
𝑑𝑈 = 𝑛𝑅𝑇
2
So, the total internal energy,
𝑓 𝑓
𝑑𝑈𝑡𝑜𝑡𝑎𝑙 = ( 𝑛𝑅𝑇) + ( 𝑛𝑅𝑇)
2 𝑚𝑜𝑛𝑜 2 𝑑𝑖𝑎
3 5 8
= 𝑛𝑅𝑇 + 𝑛𝑅𝑇 = 𝑛𝑅𝑇
2 2 2
For 𝑛 = 2 moles. We get
8
𝑑𝑈𝑡𝑜𝑡𝑎𝑙 = (2𝑚𝑜𝑙)𝑅𝑇 = 8𝑅𝑇
2
40. (a) :
The first assumption is correct because it is basic law that we take under consideration
for the ideal environment of the simple pendulum.
The second one is also correct because it is considered that angle of motion should be
negligible, 10° is one negligible angle because sine of 10° is 0.18. Any angle smaller than
will tend do zero effect in charge.
Thus, both (i) and (ii) are correct.
41. (d) :
In longitudinal waves, the vibrations are parallel to the direction of wave travel. In
transverse waves, the vibrations are at right angle to the direction of wave travel. To
possess both type of motion the material must bulk as well as shear moduli. Solid posses
both, therefore both motion is observed in solids, while gases do have longitudinal
waves.
42. (a) :
The equation of motion due to force applied is,
𝐹 = 𝑚𝑎
And electric force due to field is,
𝐹 = 𝑞𝐸 = 𝑒𝐸
The acceleration due to circular motion is,
𝑎 = 𝜔2 𝑥
So, we have
𝑒𝐸 = 𝑚𝜔2 𝑥
Therefore, electric field at the distance 𝑥 from the axis of rotation is,
𝑚𝜔2 𝑥
𝐸=
𝑒
43. (b) :
The electric field due to infinite, straight uniformly charged wire is expressed as,
𝜆
𝐸=
2𝜋𝜀0 𝑟
Where 𝜆 is linear charge density.
1
Therefore, electric is inversely proportional to the distance 𝑟, that is, 𝐸 ∝ 𝑟.
44. (c) :
The electric potential energy is expressed as,
𝑃𝐸 = 𝐸𝑄𝑥
The kinetic energy is,
1
𝐾 = 𝑚𝑣 2
2
Total energy is constant,
1
𝐸𝑄𝑥 = 𝑚𝑣 2 = 𝐾
2
𝐾
⇒𝑄=
𝐸𝑥
Given that, 𝐾 = 0.12𝐽, 𝐸⃗ = (300𝑁𝐶 −1 )𝑖 and 𝑥 = 0.5 m. Then,
0.12𝐽
𝑄= = 800𝜇𝐶
(300𝑁𝐶 −1 )(0.5𝑚)
45. (b) :
The expression for the separation and dielectric constant between a plate,
1
𝑥 = 𝑡 (1 − )
𝑘
𝑥 1
⇒1− =
𝑡 𝑘
𝑡
⇒𝑘=
𝑡−𝑥
Given that, 𝑥 = 3.5 mm and 𝑡 = 4 mm. So,
4 × 10−3 𝑚
𝑘= = 8.0
4 × 10−3 𝑚 − 3.5 × 10−3 𝑚
46. (a) :
We know that,
Volume of 8 small drop = =Volume of big drop
4 4
8 × 𝜋𝑟 3 = 𝜋𝑅 3
3 3
⇒ 𝑅 = 2𝑟
Let 𝐶 be the capacitance of smaller drop, 𝐶′ be the capacitance of bigger drop and store
in it is 𝑞. So,
𝐶 = 4𝜋𝜀0 𝑟, 𝐶 ′ = 4𝜋𝜀0 𝑅
The ratio of capacitance for smaller drop and bigger drop is,
𝐶′ 𝑅 2𝑟
= = =2
𝐶 𝑟 𝑟
47. (c) :
Polar molecule is molecule having one end slightly positive and other end slightly
negative due to difference is electronegativity of constituent molecules. Centers of
positive and negative charges are separated with or without the presence of electric
field. Due dipole in nature polar molecule has dipole moment permanently, HCl is one
polar molecule with 𝐻 + and 𝐶𝑙 − atoms.
48. (d) :
The number of capacitors in a row,
desired voltage 1500𝑉
𝑛= = =3
voltage across each capacitor 500𝑉
Given that, desired voltage = 1.5 kV and voltage across capacitor = 500 V.
1500𝑉
𝑛= =3
500𝑉
The number of rows is expressed as,
desired capacitance 6𝜇𝐹
𝑚= = =9
total capacitance in each row 2𝜇𝐹/3
Given that, desired capacitance = 6𝜇𝐹 and total capacitance in one row =
1 2
1 1 1 = 3 𝜇𝐹.
+ +
2𝜇𝐹 2𝜇𝐹 2𝜇𝐹
6𝜇𝐹
𝑚= =9
2𝜇𝐹/3
Therefore, total number of capacitance are,
𝑚 × 𝑛 = 9 × 3 = 27
49. (b) :
The capacitance is expressed as
𝑄
𝐶=
𝑉
120𝜇𝐶
=
10𝑉
= 12𝜇𝐹
Given that, 𝑄 = 120𝜇𝐶 and 𝑉 = 10𝑉. So,
120𝜇𝐶
𝐶= = 12𝜇𝐹
10𝑉
The energy stored in a capacitor is expressed as,
1
𝑈 = 𝑄𝑉
2
1
= (120𝜇𝐶)(10𝑉) = 600𝜇𝐽
2
50. (d) :
The resistance is expressed as,
𝜌𝑙
𝑅= 𝐴
(1)
′ ′
Given that, 𝑙 = 2𝑙 then 𝐴 = 𝐴/2. Since, the length of wire gets doubled, the cross-
sectional area will become half because volume of wires remains constant.
The new resistance is,
𝜌(2𝑙)
𝐸′ = (2)
𝐴/2
from (1)and (2), we get
𝜌(2𝑙)
𝑅′ 𝐴/2
=
𝑅 𝜌𝑙
𝐴
⇒ 𝑅 ′ = 4𝑅
Given that 𝑅 = 3Ω. So,
𝑅 ′ = 4(3Ω) = 12Ω
51. (a) :
The meter bridge works on the principle of Wheatstone bridge. That is,
𝑅1 𝑅2 𝑅1 𝑅𝐴𝐷 𝑥
= ⇒ = =
𝑅𝐴𝐷 𝑅𝐷𝐵 𝑅2 𝑅𝐷𝐵 100 − 𝑥
The balancing length is independent of area of cross section of the wire AB. Thus, there
will be no change no charge in 𝑥 due to doubling of wire cross-section AB.
52. (d) :
The drift velocity relation for electron is,
𝐼
𝑣𝑑 =
𝑛𝑒𝐴
Here 𝐼 = 1𝐴, 𝑛 = 8 × 1028 𝑚−3 , 𝑒 = 1.6 × 10−19 𝐶 and 𝐴 = 5 × 10−7 𝑚2 . So,
1𝐴 1
𝑣𝑑 = = 𝑚/𝑠
(8 × 10 )(1.6 × 10 𝐶)(5 × 10 𝑚 ) 6.4 × 103
28 −19 −7 2
The time taken by electron take to drift one end to the other end of 1m wire is,
𝐿 1𝑚
𝑇= = = 6.4 × 103 𝑠
𝑣𝑑 ( 1
𝑚/𝑠)
6.4 × 103
53. (b) :
There is electrical conductor connected across the voltage 𝑉. The motion will be
assumed to be conserved. It means loss in potential energy is equal to the gain in kinetic
energy. So,
∆𝐾 = −∆𝑈
Therefore, for the given case there is increase in kinetic energy and decrease in
potential energy,
The potential energy is expressed as,
∆𝑈 = −𝐼𝑉∆𝑡
And ∆𝐾 = −∆𝑈 = 𝐼𝑉∆𝑡
54. (c) :
Due to strong magnetic field on a stationary electron, there will be attraction force to
both external magnetic poles, cancelling each other so the net force on the electron will
always be zero, causing the electron to remain stationary. Magnetic force act on moving
change particles.
55. (a) :
The force exerted by one wire, having current 𝐼1 , on the other parallel wire having
current 𝐼2 , per unit length is expressed as,
𝐹 𝜇0 𝐼1 𝐼2
=
𝐿 2𝜋𝑟
Where, 𝑟 is separation of wire.
Here, 𝜇0 = 4𝜋 × 10−7 𝑁𝐴−2 , 𝐼1 = 𝐼2 = 10𝐴 and 𝑟 = 10 cm. So,
𝐹 (4𝜋 × 10−7 𝑁𝐴−2 )(10𝐴)(10𝐴)
= = 2 × 10−4 𝑁𝑚−1
𝐿 2𝜋(10 × 10−2 𝑚)
The force will be attractive.
56. (d) :
A toroid is a donut-shaped coil closely wound with one continuous wire. So, the
direction of magnetic field due to inner surface is opposite to the direction of magnetic
field due to outer surface.
We have to find magnetic field in three regions I, II and III as shown in the following
figure
The magnetic field due to inner and outer surface at region II is given by Ampere’s
circuital law, that is,
𝐵𝐼𝐼 = 𝜇0 𝑛𝐼
Where, 𝑛 number of turns per unit length and it is given by
𝑁 𝑁
𝑛= =
2𝜋𝑟 2𝜋 ( 1 + 𝑅2 )
𝑅
2
𝜇0 𝑁𝐼
Then, 𝐵𝐼𝐼 = 𝜋(𝑅 +𝑅 )
1 2
Magnetic field outside the toroid is zero, that is 𝐵𝐼 and 𝐵𝐼𝐼𝐼 = 0
So, the best graph is represents the magnetic field due to toroid is,
57. (b) :
When centripetal force is equal to magnetic force, than particle does not strike the
solenoid. That is,
𝑚𝑣 2 𝑞𝐵𝑅
= 𝑞𝑣𝐵 ⇒ 𝑣 =
𝑅 𝑚
Here 𝑅 = 𝑟/2. So,
𝐵𝑞𝑟
𝑣=
2𝑚
The magnetic field of solenoid is,
𝐵 = 𝜇0 𝑛𝐼
So, the velocity is,
(𝜇0 𝑛𝐼) 𝜇0 𝑛𝐼𝑞𝑟
𝑣= =
2𝑚 2𝑚
58. (b) :
The horizontal components are known as latitude and vertical components are called
longitude. Equator is latitude and largest horizontal line. At the magnetic poles there is
no latitudes as it is junction of longitudes. So, at magnetic poles Earth’s magnetic field
do not have horizontal component.
59. (c) :
The option (a) is positive electric monopole while option (b) is negative. And monopoles
do not exist for magnetic field. Option (d) shows magnetic field of the magnet having
North and South poles or dipoles, but dipoles do not exist in electric field. The only
option here which is analogous to both electric magnetic and electric field is option (c),
as time varying magnetic field causes time varying electric field.
60. (*) :
The emf induced due to self-inductance is expressed as,
𝑑𝐼
𝐸 = −𝐿
𝑑𝑡
From the given graph, we have
𝐼1 = 4𝐴 at 20 s
And, 𝐼2 = 3𝐴 at 40 s
(3𝐴−4𝐴)
So, 𝐸 = −(6𝑚𝐻) (40𝑠−20𝑠) = 3.0 × 10−4 𝑉
None of the option matches.
CHEMISTRY
1. (c): In colloids, the potential difference between a fixed layer and diffused layer of the opposite
charge is called as Zeta potential.
2. (b): The decomposition reactions of the given compounds are given below:
∆
i. Pb(NO3 )2 → PbO + 2NO2 + O2
∆
ii. NH4 NO3 → N2 O + 2 H2 O
∆
iii. NH4 NO2 → N2 + 2H2 O
∆
iv. 2 NaNO3 → 2NaNO2 + O2
Hence, only NH4 NO3 will decompose to give N2 O.
3. (b, c): Down the group the electronegativity decreases and the atomic size increases, therefore,
the bond length decreases so as the thermal stability decreases in same order.
4. (b): The boiling point is depended on strength of hydrogen bond and the molecular mass.
Although F is more electronegative than O but, H2 O form four hydrogen bonds while HF form
two hydrogen bond.
25. (d): According to conjugate acid – base theory, a weak acid produces a strong conjugate base
and vice-versa. That is, smaller the value of Ka, weaker will be the acid. Therefore, HCN
(k a = 4 × 10−10 ) is weakest acid among the given acid. Therefore, it will give strongest
conjugate base that is CN-.
HCN ⇌ H + + CN −
26. (c): Only acetylene CH ≡ CH) gives acetaldehyde through oxymercuration reaction. The
reaction involved is
HgSO4 /H2 SO4
HC ≡ CH CH3 CHO
⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗
H2 O
(A) (Acetaldehyde)
Acetylene
Ethanol on oxidation with PCC gives CH3 CHO. The reaction involved is
PCC
CH3 CH2 OH ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗ CH3 CHO
(oxidation)
(B) (Acetaldehyde)
Ethanol
Reduction of alkyl nitriles with SnCl2 /HCl is an example of Stephen reduction reaction. The
reaction involved is
(i)SnCl2 /HCl
CH3 CN ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗+ CH3 CHO
(ii)H3 O
(c) (Acetaldehyde)
Methyl nitrile
27. (a): A carboxylic acid can be reduced by LiAlH4/ether. Therefore, the reaction involved is
LiAlH4
CH3 − COOH CH3 CH2 OH
⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗
ether
28. (b): The reaction involved is
OH
|
(i)CH MgBr
3
CH3 − CHO ⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗⃗
+
CH3 − C − CH3
(ii)H3 O
|
H
(A)
(Propan – 2 – ol)
Conc.n H2 SO4 ↓ ∆(−H2 O)
(i)B2 H6
CH3 − CH2 − CH2 − OH CH3 − CH = CH2
←
(ii) H2 O2 / OH−
(C) (B)
(Propan – 1 – ol)
The compound (A) and (C) are position isomers as position of −OH group has changed.
29. (d): An oxidation process involves the addition of oxygen atoms, removal of electrons, addition
of electronegative element as well as removal of H – atoms from an atom. Whereas removal of
electronegative atom does not count as oxidation.
30. (c): The given transformation can be carried out by using iodoform regents followed by
acidification. Since, I2 / NaOH is a weak oxidizing agent, therefore the double bond is
unaffected. The reaction involved is
(i) I2 / NaOH
CH3 CH = CHCH2 COCH3 → CH3 CH = CHCH2 CO O− Na+ + CHCl3
(ii) H2 O+
CH3 CH = CHCH2 CO O− Na+ → CH3 CH = CHCH2 COOH
31. (a): The reaction involved is
33. (c): Permanent hardness of water is removed by using washing soda, Calgon’s method and ion
exchange method. However temporary hardness of water is removed by Clark ′ s method.
Ca(OH)2 is Clark’s reagent. It removes hardness of water by converting bicarbonates into
carbonates.
Ca(OH)2 + Ca (HCO3 )2 → 2CaCO3 ↓ +H2 O
34. (b): Compound (A) which gives only one compound on addition with HCl. The possible structure
of A is
HCl
CH3 − CH = CH − CH3 → CH3 − CH − CH2 − CH3
(A) |
Cl
↓ NH3 (1mol)
(i)NaNO2 / HCl
CH3 − CH − CH2 − CH3 ← CH3 − CH − CH2 − CH3
(ii) H2 O
| |
OH NH2
(D)
35. (a): RNA and DNA contains D – ribose and Deoxyribose sugars, which are D − Chiral sugars.
These sugars result in the optical activity of DNA and RNA
36. (c): Moving down the group in alkaline earth metals:
(i) Electropositive of alkaline earth metals increases as size increases.
(ii) Ionization energy decreases as size increases.
(iii) Solubility of their hydroxide in water.
Be(OH)2 < Mg(OH)2 < Ca(OH)2 < Sr(OH)2 < Ba(OH)2
(iv) Solubility of their sulphate in water.
37. (c): In nuclei acids, the pairing bases are as follows:
G ≡ C and A = T
The complementary sequence of the given chain is given below:
G≡C
A=T
T=A
G≡C
C≡G
Therefore, CTACG is the complimentary chain.
38. (a): The metal chloride salt is treated with sulphuric acid, which produces hydrogen chloride gas.
MCl + H2 SO4 → MHSO4 + HCl
39. (a): The Buckminster fullerene has 20 six membered ring whereas 12 five membered rings.
40. (b): Oxide ions occupy CCP close packing, therefore no. of oxygen atoms (N)=4
IN CCP, no. of octahedral voids (N) =4
1
Therefore, No. Of Be2+ ion = × 4 = 1
4
No. of tetrahedral voids 2N = 8
1
No. of Al3+ ions 4 × 8 = 2
Hence, the formula of compound is BeAl2 O4
41. (c): (i) Frankel defect is known as dislocation defect. In which a smaller ion (cation) is dislocated
from its normal site to interstitial site. It creates a vacancy defect at its original site and an
interstitial defect at its new location.
(ii) Schottky defect is a vacancy defect in ionic solids.
(iii) Trapping of an electron in the lattice leads to the formation of F − centre is correct.
42. (c): We know
Z×M
ρ= 3 … (1)
a × NA
For BCC, Z = 2
Substituting the values in equation (1), we get
2×M
6.15 gcm−3 =
(3 × 10−8 cm)3 × 6.022 × 1023 /mol
6.15 g cm−3 × 27 × 10−24 cm3 × 6.022 × 1023 /mol
⇒M=
2
⇒ M = 50 gmol−1
Hence molar mass of metal is 50 gmol−1
43. (a): Given,
Mole fraction of N2 = 0.8, pT = 5 atm
From Dalton′ s law, we have
PN2 = xN2 × pN2 = 0.8 × 5 atm
pN2 = 4 atm
From Henry’s law, we have
pN2 = k N2 xN2
Susbtituting the values in eq. (1), we get
nN
4 atm = 1.0 × 105 atm × 2
10
Thus, nN2 = 4 × 10−4
44. (d): Given, Mass of C = 2.4 g
No. of H − atoms = 1.2 × 1023 atoms
Moles of O atoms = 0.2 moles
2.4 g
The No. moles of C = = 0.2 mol
12 gmol−1
Using the number of H – atoms, moles of H atoms are calculated as follows:
We know
1 mole = 6.022 × 1023 atoms
1.2 × 1023 atoms
⇒ Moles of H − atoms = = 0.2 mol
6.022 × 1023 atoms/mol
Therefore, empirical formula = C0.2 H0.2 O0.2
Or C1 H1 O1 ≈ CHO
45. (d): (1) k H value is different for a gas in any solvent, as it depends on the solvent.
(2) According to Dalton’s law: Solubility ∝ pressure,
p = kH ∙ x
Therefore, solubility inversely proportional to k H . So more the value of k H less will be solubility.
(3): k H value increases on increasing the temperature correct.
(4): The gases which liquifies easily has less value of k H , correct
46. (a): According to Henry’s law, we have
p = kH ∙ x
p
or x =
kH
Thus, solubility is inversely proportional to k H . More than value of k H less will be the solubility.
Gases k H Values
I. Argon 40.3
II. Carbon dioxide 1.67
III. Formaldehyde 1.83 × 10−5
IV. Methane 0.413
Hence, the correct increasing order of solubility of gas in liquid is I < II < IV < III
47. (a): Given, poA = 450 mm Hg, poB = 700 mm Hg
pT = 600 mm Hg xA =? xB =?
pT = pA + pB = pA ∙ poA + xB ∙ poB
Or pT = xA ∙ poA + (1 − xA )poB (since, xA + xB = 1)
Thus, 600 = xA × 4500 + 700 − 700 xA
600 − 700 = (450 − 700)xA
100
⇒ 100 = 250xA ⇒ xA = = 0.4
250
Therefore, xB = 1 − xA = 1 − 0.4 = 0.6
Hence, the comoposition of mixture is ∶ xA = 0.4 and xB = 0.6
48. (c): From Nernst equation, we have
0.0591 [P]
Ecell = E 0 − log
n [R]
For the given half-cell reaction,
Zn → Zn2+ + 2e−
We have
Ecell ∝ [P]
Since in above reaction product is Zn2+ , so more the concentration of Zn2+ ions, more will be
the Ecell . Hence, the correct order of Ecell is:
Q>R>S>P
49. (b): Number of angular nodes = l
Number of radial nodes = n − l − 1
For 3p, n = 3
l = 1,
Therefore, angular nodes (l) = 1
Radial nodes = 3 − 1 − 1 = 1
50. (a): Given, R = 1500 Ω, concentration = 0.01 m
l
Conductivity (k) = 0.146 × 10−3 S cm−1 , Cell constant A =?
We know
A
R = ρ( )
l
1 1 l
⇒ = ∙( )
R ρ A
1 l
or = k ∙ ( ) … (1)
R A
Substituting the values in equation (1), we get
l
⇒ = k ∙ R = 0.146 × 10−3 S cm−1 × 1500 S −1
A
= 219 × 10−1 cm−1 = 0.219 cm−1
51. (a): We know
o 0.0591
Ecell = log k eq
n
From the given chemical reactions,
H2 + 2AgCl ⇌ 2 Ag(s) + 2 HCl
2AgCl + 2e− ⇌ 2Ag(s) + 2Cl−
The change in number of moles n = 2
Substituting the values in eq. (1), we get
0.0591
0.22 = log k eq
2
0.22 × 2
⇒ log k eq = = 7.457
0.0591
⇒ k eq = Antilog(7.457) = 2.8 × 107
52. (a): For the given reaction
A + 2B → P
The rate expression is
Rate = k[A]α [B]β [Where α and β are order w. r. t A and B]
When [B] is increased, half-life remains same, this implies that [B] does not affect t1/2.
0.693
t1 = [First − order reaction]
2 k
Therefore, α = 0,
Hence, the rate expression becomes
Rate = k[A]0 [B]1
Or Rate = k[B]1
⇒ The overall order of reaction is 1.0
So, the unit of rate constant (k) = s −1
53. (b): Since, the general electronic configuration of alkaline earth metals is ns2. Therefore, after
the two ionization enthalpies, the electronic configuration of alkaline earth metals becomes ns0,
that is, a noble gas configuration, which required higher third ionization energy to extract from
noble gas configuration.
54. (b): We know, For first order reaction:
2.303 [A]0
t= log
k [A]1
For 99% completion: [A]1 = 100 − 99 = 1%
2.303 100
t 99% = log
t 1
2.030
⇒ t 99% = ×2 [Since, log 100 = 2]
k
4.606
⇒ t 99% =
k
55. (c): The rate expression is
Rate0 = k[A][B]2 for gaseous reaction
1 V1
⇒ p ∝ so, when V2 =
V 2
1 2
⇒p= = , pressure becomes double
V1 V1
2
Hence, the rate expression becomes
⇒ Rate1 = k[2A]1 [2B]2
⇒ Rate1 = 8k[A]1 [B]2
⇒ Rate1 = 8Rate0 ⇒⇒
56. (a): The correct IUPAC name of the given compound is
4. π − Electrons are known as mobile electrons. For example, in benzene, the π − electrons are
delocalized over the ring in benzene.
MATHEMATICS
|𝑏| ̅ |𝑏| ̅
So, tan 60° = |𝑎̅| ⇒ √3 = |𝑎̅| ⇒ √3|𝑎̅| = |𝑏̅|
15. (c) :
Given that, |𝑎̅ × 𝑏̅| = 15
If the sides are (3𝑎̅ + 2𝑏̅) 𝑎𝑛𝑑 (𝑎̅ + 3𝑏̅) . then area is given by
Area = |(3𝑎̅ + 2𝑏̅) × (𝑎̅ + 3𝑏̅)|
= |2(𝑏̅ × 𝑎̅) + 9(𝑎̅ × 𝑏̅)| = |−2(𝑎̅ × 𝑏̅) + 9(𝑎̅ × 𝑏̅)|
= 7|𝑎̅ × 𝑏̅| = 7(15) = 105 Sq. units.
16. (b) :
We know that the equation of the line passing through the points (𝑥1 , 𝑦1 , 𝑧1 ) and
(𝑥2 , 𝑦2 , 𝑧2 ) is given by
𝑥 − 𝑥1 𝑦 − 𝑦1 𝑧 − 𝑧1
= =
𝑥2 − 𝑥1 𝑦2 − 𝑦1 𝑧2 − 𝑧1
Given that points are (-3, 4, 11) and (1, -2, 7). So, the equation of the line is given by
𝑥+3 𝑦−4 𝑧 − 11
= =
1 + 3 −2 − 4 7 − 11
𝑥 + 3 𝑦 − 4 𝑧 − 11
⇒ = =
4 −6 −4
Clearly the directives of the line are proportional to -2, 3, 2
𝑥+3 𝑦−4 𝑧−11
Therefore, the required equation of line is −2
= 3
= 2
17. (c):
√3 2 √3
Given that, (𝑙1 , 𝑚1 , 𝑛1 )= ( 4 , 4 , 2
) and
√3 1 −√3
(𝑙2 , 𝑚2 , 𝑛2 )= ( 4 ,4, 2 )
So, angle between the lines are given by
|𝑙1 𝑙2 + 𝑚1 𝑚2 + 𝑛1 𝑛2 |
cos 𝜃 =
√𝑙12 + 𝑚12 + 𝑛12 × √𝑙22 + 𝑚22 + 𝑛22
3 1 3
|16 + 16 − 4|
−1
= | =|
√1√1 2
1 𝜋
⇒ cos 𝜃 = ⇒ 𝜃 =
2 3
18. (b) :
Let the plan meets the coordinate axes at the points A(a, 0, 0), B(0, b, 0) and C(0, 0, c).
the centroid of the triangle
𝑎 𝑏 𝑐
ABC is 𝑂 = (3 , 3 , 3).
Given that, centroid 𝑂 = (1, 2, 3). So,
𝑎 𝑏 𝑐
( , , ) = (1, 2, 3)
3 3 3
⇒ 𝑎 = 3, 𝑏 = 6, 𝑐 = 9
Now, the equation of plane in intercept form is given by
𝑥 𝑦 𝑧
+ + =1
𝑎 𝑏 𝑐
𝑥 𝑦 𝑧
⇒ + + =1
3 6 9
19. (a) :
Given that, ABCD is a quadrilateral, where A = (0, 4, 1), B = (2, 3, -1), C = (4, 5, 0) and D =
(2, 6, 2).
Area of quadrilateral is given by
Area of quadrilateral = (Area of ∆𝐴𝐵𝐷) +(𝐴𝑟𝑒𝑎 𝑜𝑓 ∆𝐵𝐶𝐷)
1 1
= |𝐴𝐵 ̅̅̅̅ × ̅̅̅̅ ̅̅̅̅ × ̅̅̅̅
𝐴𝐷 | + |𝐶𝐵 𝐶𝐷|
2 2
1 1
= |3𝑖̂ − 6𝑗̂ + 6𝑘̂ | + |−3𝑖̂ + 6𝑗̂ − 6𝑘̂ |
2 2
1 1 1 1 1
= 2 √81 + 2 √81 = 2 (9) +2 (9) =2 (18) = 9 sq. unit
20. (c) :
From the given shaded region in the figure, we can see four lines bounded the shaded
region.
The three lines are given as
𝑥 = 6, 𝑦 = 0 and 𝑦 = 3
Other line is given as
−5
𝑦= 𝑥 + 5 ⇒ 5𝑥 + 4𝑦 = 20
4
To make a given shaded region we have following inequalities from there four lines are
5𝑥 + 4𝑦 ≥ 20, 0 ≤ 𝑥 ≤ 6, 0 ≤ 𝑦 ≤ 3
Or 5𝑥 + 4𝑦 ≥ 20, 𝑥 ≤ 6, 𝑦 ≤ 3, 𝑥 ≥ 0, 𝑦 ≥ 0
21. (2) :
3 1 4
Given that, 𝑃(𝐵) = 5 , 𝑃(𝐴/𝐵) = 2 and 𝑃(𝐴 ∪ 𝐵) = 5.
We know that,
𝑃(𝐴 ∪ 𝐵) = 𝑃(𝐴) + 𝑃(𝐵) − 𝑃(𝐴 ∩ 𝐵)
𝑃(𝐴∩𝐵)
Since, 𝑃(𝐴/𝐵) = 𝑃(𝐵)
⇒ 𝑃(𝐴 ∩ 𝐵) = 𝑃(𝐴/𝐵) ∙ 𝑃(𝐵)
Then, 𝑃(𝐴 ∪ 𝐵) = 𝑃(𝐴) + 𝑃(𝐵) − 𝑃(𝐴/𝐵) ∙ 𝑃(𝐵)
4 3 1 3
⇒ = 𝑃(𝐴) + − ( ) ( )
5 5 2 5
1
⇒ 𝑃(𝐴) =
2
22. (c) :
Given that, 𝑃(𝐴) = 𝑃(𝐵) = 𝑃(𝐶) = 𝑃
𝑃(at least 2 of 𝐴, 𝐵, 𝐶 occur)
= 𝑃(𝐴 ∩ 𝐵 ∩ 𝐶 ′ ) + 𝑃(𝐴 ∩ 𝐵′ ∩ 𝐶) + 𝑃(𝐴′ ∩ 𝐵 ∩ 𝐶) + 𝑃(𝐴 ∩ 𝐵 ∩ 𝐶)
𝑃(𝐴)𝑃(𝐵)𝑃(𝐶′) + 𝑃(𝐴)𝑃(𝐵′)𝑃(𝐶) + 𝑃(𝐴′)𝑃(𝐵)𝑃(𝐶) + 𝑃(𝐴)𝑃(𝐵)𝑃(𝐶)
= 𝑃2 (1 − 𝑃) + 𝑃2 (1 − 𝑃) + 𝑃2 (1 − 𝑃) + 𝑃3 = 3𝑃2 − 2𝑃3
23. (c) :
Given that, 𝐸 = {(1, 1)(1, 2)(1,3)(1, 4)(2, 1)(2, 2)(2, 3)(3, 1)(3, 2)(4, 1)} 𝑎𝑛𝑑 𝐹 =
{(1, 2)(2, 1)}
So, probability of getting a sum as 3 is
𝐹 2 1
𝑃( ) = =
𝐸 10 5
24. (3) :
Let 𝐸1 be the event of plant 𝑋 manufacturing car, 𝐸2 be the event of plant 𝑌
manufacturing car and 𝐴 be event car is of standard quality. So, the probability when a
car chosen at random it has come from plant 𝑋 is given by
𝑃(𝐸1 ) ∙ 𝑃(𝐴/𝐸1 )
𝑃(𝐸1 /𝐴) =
𝑃(𝐸1 ) ∙ 𝑃(𝐴/𝐸1 ) + 𝑃(𝐸2 ) ∙ 𝑃(𝐴/𝐸2 )
Given that, 𝑃(𝐸1 ) = 0.7, 𝑃(𝐸2 ) = 0.3, 𝑃(𝐴/𝐸1 ) = 0.8 and 𝑃(𝐴/𝐸2 ) = 0.9. so,
𝐸1 0.7 × 0.8 56
𝑃( ) = =
𝐴 0.7 × 0.8 + 0.3 × 0.9 83
25. (b) :
Let the total families in the town be 𝑥, families own cell phones be 𝐴 and families own
scooter be 𝐵.
Given that, 65% of 𝑥 have cell phones, 15000 have scooter and 15% of 𝑥 have both.
So, total number of families is given by
𝑛(𝐴 ∪ 𝐵) = 𝑛(𝐴) + 𝑛(𝐵) − 𝑛(𝐴 ∩ 𝐵)
65 15
⇒𝑥= 𝑥 + 15,000 − 𝑥
100 100
⇒ 𝑥 = 0.5𝑥 + 15,000
1
⇒ 𝑥 = 15,000 ⇒ 𝑥 = 30,000
2
26. (d) :
Given that, 𝑛(𝐴 × 𝐵) = 35.
If 𝐵 ⊂ 𝐴, then 𝑛(𝐵) = 5, 𝑛(𝐴) = 7.
7×6
Therefore, 𝑛(𝐴)𝐶𝑛(𝐵) = 7𝐶5 = 2
= 21
27. (d) :
𝑥
Given that, 𝑓(𝑥) = 1−|𝑥|
So, |𝑥| ≠ 1
Therefore, domain = 𝑅 − {−1, +1}
28. (a):
Given that, cos 1200° + tan 1485°
= cos[1080° + 120°] + tan[1440° + 45°]
= cos[(180 × 6)° + 120°] + tan[(180 × 8)° + 45°]
= cos 120° + tan 45° = cos(180° − 60°) + 1
−1 1
= − cos 60° + 1 = +1=
2 2
29. (2) :
Given that, tan 1° ∙ tan 2° … … . tan 89°
tan 1° ∙ tan 2° … tan 45° … . tan(90 − 2)° tan(90 − 1)°
tan 1° ∙ tan 2° … tan 45° … . . cot 2° cot 1° = tan 45° = 1
30. (d) :
1+𝑖 𝑥
Given that, (1−𝑖) = 1
1+𝑖
We know that, (1−𝑖) = 𝑖
⇒ 𝑖 𝑥 = 1 ⇒ 𝑖 4𝑛 = 1
Therefore, 𝑥 = 4𝑛, 𝑛 ∈ ℕ
31. (a):
Given that, 𝐶(𝑥) = 20𝑥 + 4000 and 𝑅(𝑥) = 60𝑥 + 2000.
For earn profit, we want
𝑅(𝑥) − 𝐶(𝑥) > 0
⇒ 60𝑥 + 2000 − 20𝑥 − 4000 > 0
⇒ 40𝑥 > 2000
2000
⇒𝑥> ⇒ 𝑥 > 50
40
32. (c) :
Given that, part 𝐴 have 6 questions and part 𝐵 have 7 questions.
We have the following ways to choose 10 questions from parts 𝐴 and :
A B Number of selections
4 6 6×5
6𝐶4 × 6𝐶6 = ×7
2
= 105
5 5 7×6
6𝐶5 × 7𝐶5 = 6 ×
2
= 126
6 4 7×6×5
6𝐶6 × 7𝐶4 = 1 ×
2
= 35
𝑛2 − 1
𝜎=√
12
Here 𝑛 = 17. Therefore, standard deviation is
172 − 1 288
𝜎=√ =√ = 2√6
12 12
39. (c) :
Given that, 𝑃(𝐴) = 0.59, 𝑃(𝐵) = 0.03 and 𝑃(𝐴 ∩ 𝐵) = 0.21.
So,
𝑃(𝐴′ ∩ 𝐵′) = 𝑃(𝐴 ∪ 𝐵)′
= 1 − 𝑃(𝐴 ∪ 𝐵)
= 1 − [𝑃(𝐴) + 𝑃(𝐵) − 𝑃(𝐴 ∩ 𝐵)]
= 1 − 0.68 = 0.32
40. (d):
Given that,
2𝑥; 𝑥 > 3
𝑓(𝑥) = {𝑥 2 ; 1 < 𝑥 ≤ 3
3𝑥; 𝑥 ≤ 1
Then, 𝑓(−2) + 𝑓(3) + 𝑓(4) = 3(−2) + 32 + 2(4)
= −6 + 9 + 8 = 11
41. (a) :
2𝑥
Let 𝐴 = {𝑥: 𝑥 ∈ 𝑅; 𝑥 𝑖𝑠 𝑛𝑜𝑡 𝑎 𝑝𝑜𝑠𝑖𝑡𝑖𝑣𝑒 𝑖𝑛𝑡𝑒𝑔𝑒𝑟} and define 𝑓: 𝐴 → 𝑅 as 𝑓(𝑥) = 𝑥−1
Check for one-one function,
∀𝑥1 , 𝑥2 ∈ 𝐴
𝑓(𝑥1 ) = 𝑓(𝑥2 )
2𝑥1 2𝑥2
=
𝑥1 − 1 𝑥2 − 1
𝑥1𝑥2 − 𝑥1 = 𝑥1 𝑥2 − 𝑥2
𝑥1 = 𝑥2
So, 𝑓 is one-one function.
Now check for onto function,
2𝑥
𝑦=
𝑥−1
𝑥𝑦 − 𝑦 = 2𝑥
𝑥𝑦 − 2𝑥 = 𝑦
𝑥(𝑦 − 2) = 𝑦
𝑦
𝑥= ∉𝐴
𝑦−2
So, 𝑓 is not onto function.
42. (a) :
Given that, function 𝑓(𝑥) = √3 sin 2𝑥 − cos 2𝑥 + 4
√3 1
⇒ 𝑓(𝑥) = 2 { sin 2𝑥 − cos 2𝑥} + 4
2 2
𝜋 𝜋
= 2 {sin 2𝑥 cos − cos 2𝑥 sin } + 4
2 2
𝜋
= 2 {sin (2𝑥 − )} + 4
6
−𝜋 𝜋
sin 𝑥 is one-one in [ , ]. So,
2 2
−𝜋 𝜋 𝜋
≤ 2𝑥 − ≤
2 6 2
𝜋 𝜋 𝜋 𝜋
⇒ 6 − 2 ≤ 2𝑥 ≤ 2 + 6
−𝜋 2𝜋
⇒ ≤ 2𝑥 ≤
3 6
−𝜋 𝜋 −𝜋 𝜋
⇒ 6
≤𝑥≤ 3
⇒ 𝑥 ∈ [ 6 , 3]
43. (a) :
1
Given that, function 𝑓(𝑥) =
√[𝑥]2 −[𝑥]−6
So, [𝑥]2 − [𝑥] − 6 > 0
44. (d):
𝜋
Given that, cos [cot −1 (−√3) + ]
6
−1
𝜋 𝜋
= cos [cot cot (𝜋 − ) + ]
6 6
𝜋 𝜋
= cos (𝜋 − + ) = cos 𝜋 = −1
6 6
45. (*) :
1 5𝜋 √3
Given that, tan−1 [ sin ] sin−1 [cos (sin−1 )]
√3 3 2
−1 1 𝜋 −1 −1 𝜋
, tan [ 3 sin (2𝜋 + 2 )] sin [cos (sin sin ( 3 ))]
√
1 𝜋 𝜋
tan−1 [ sin ( )] sin−1 [cos ( )]
√3 2 3
1 1
tan−1 [ (1)] sin−1 [ ]
√3 2
𝜋 𝜋
tan−1 [tan ( )] sin−1 [sin ( )]
6 6
𝜋 𝜋 𝜋2
= ∙ =
6 6 36
46. (b) :
2 1
1 −2 1
Given that, 𝐴 = [ ] and 𝐵 = [3 2]. Then,
2 1 3
1 1
2 1
1 −2 1 2−6+1 1−4+1
𝐴𝐵 = [ ] [ 3 2] = [ ]
2 1 3 4+3+3 2+2+3
1 1
−3 −2
𝐴𝐵 = [ ]
10 7
−3 10
So, (𝐴𝐵)′ = (𝐴𝐵)𝑇 = [ ]
−2 7
47. (c) :
For matrix to be invertible, determinant must not be equal to zero, that is matrix should
be non-singular.
𝑎 ℎ
Let matrix be 𝑀 = ( ) then its determinant is |𝑀| = 𝑎𝑏 − ℎ2 ≠ 0 ⇒ 𝑎𝑏 ≠ ℎ2
ℎ 𝑏
Therefore, 𝑀 is a diagonal matrix with non-zero entries in the main diagonal of 𝑀 is not
the square of an integer.
48. (b) :
Given that, matrix of order 3 and |𝐴| = 5, |𝐵| = 3.
Then, |3𝐴𝐵| = 33 |𝐴||𝐵| (since, |𝑘𝐴| = 𝑘 𝑛 |𝐴|)
= 33 (5)(3) = 27(15) = 405
49. (4) :
Given that, A and B are invertible matrices.
So,(𝐴 + 𝐵)′ = 𝐴′ + 𝐵′ ⇒ (𝐴 + 𝐵)𝑟 = 𝐴𝑟 + 𝐵𝑟
But (𝐴 + 𝐵)−1 = 𝐵−1 + 𝐴−1 is not correct.
50. (a):
cos 𝑥 1 0
Given that, 𝑓(𝑥) = | 0 2 cos 𝑥 3 |
0 1 2 cos 𝑥
Expand along first column, we get
= cos 𝑥 (4 cos2 𝑥 − 3) − 0(0 − 2 cos 𝑥) + 0(3 − 0)
= 4 cos3 𝑥 − 3 cos 𝑥 = cos 3𝑥
So, 𝑓(𝑥) = cos 3𝑥
Therefore, lim 𝑓(𝑥) = cos 3𝜋 = −1
𝑥→𝜋
1 2 3
51. Given that, 𝑥 3 − 2𝑥 2 − 9𝑥 + 18 = 0 and 𝐴 = |4 𝑥 6|.
7 8 9
Now find the value of 𝑥 from given equation
𝑥 3 − 2𝑥 2 − 9𝑥 + 18 = 0
⇒ 𝑥 2 (𝑥 − 2) − 9(𝑥 − 2) = 0
⇒ (𝑥 2 − 9)(𝑥 − 2) = 0
⇒ (𝑥 − 3)(𝑥 + 3)(𝑥 − 2) = 0
⇒ 𝑥 = 2, 3, −3
For 𝑥 = 2, we get
1 2 3
𝐴 = | 4 2 6|
7 8 9
= 1[(2 × 9) − (6 × 8)] − 2[(4 × 9) − (6 × 7)] + 3[(4 × 8) − (2 × 7)]
= [18 − 48] − 2[36 − 42] + 3[32 − 14]
= −30 + 12 + 54 = 36
For 𝑥 = 3, we get
1 2 3
𝐴 = | 4 3 6|
7 8 9
1[(3 × 9) − (6 × 8)] − 2[(4 × 9) − (6 × 7)] + 3[(4 × 8) − (3 × 7)]
= [27 − 48] − 2[36 − 42] + 3[32 − 21]
= −21 + 12 + 33 = 24
For 𝑥 = −3, we get
1 2 3
𝐴 == |4 −3 6|
7 8 9
1[(−3 × 9) − (6 × 8)] − 2[(4 × 9) − (6 × 7)] + 3[(4 × 8) − (−3 × 7)]
= [−27 − 48] − 2[36 − 42] + 3[32 + 21]
= −75 + 12 + 159 = 96
So, the maximum value of 𝐴 is 96.
52. (b) :
𝑥3 − 1 1<𝑥>∞
Given that, 𝑓(𝑥) = {
𝑥 − 1, ∞<𝑥≥1
3
At 𝑥 = 1, 𝑓(𝑥)𝑥=1 at LHL = (1) − 1 = 0 and 𝑅𝐻𝐿 = 1 − 1 = 0. So, 𝑅𝐻𝐿 = 𝐿𝐻𝐿.
Therefore, 𝑓(𝑛) is continuous
Now, 𝑅𝐻𝐷 = 𝑅{𝑓′(𝑥)} = 3𝑥 2 = 𝑅{𝑓′(1)} = 3(1)2 = 3
𝐿𝐻𝐷 = 𝐿{𝑓′(1)} = 1 = 𝐿{𝑓′(1)} = 1
𝐿𝐻𝐷 ≠ 𝑅𝐻𝐷
Therefore, 𝑓(𝑛) is not differentiable
53. (c) :
Given that, 𝑦 = (cos 𝑥 2 )2
𝑑𝑦
So, 𝑑𝑥
= 2(cos 𝑥 2 )(− sin 𝑥 2 )2𝑥
= −4𝑥 cos 𝑥 2 sin 𝑥 2 = −2𝑥(2 cos 𝑥 2 sin 𝑥 2 ) = −2𝑥 sin(2𝑥 2 )
54. (b) :
𝑑
Given that, (𝑥 𝑥 + 𝑥 𝑎 + 𝑥 𝑥 + 𝑥 𝑎 )
𝑑𝑥
𝑑 𝑑 𝑑 𝑑
= 𝑑𝑥 (𝑥 𝑥 ) + 𝑑𝑥 (𝑥 𝑎 ) + 𝑑𝑥 (𝑥 𝑥 ) + 𝑑𝑥 (𝑥 𝑎 )
𝑥 (1 𝑎−1 𝑥
=𝑥 + log 𝑥) + 𝑎𝑥 + 𝑎 log 𝑎 + 0
𝑥 (1 𝑎−1
=𝑥 + log 𝑥) + 𝑎𝑥 + 𝑎 𝑥 log 𝑎
55. (a) :
Given that, statement 1 : 𝑦 = log10 𝑥 + log 𝑒 𝑥 and statement 2 :
𝑑 log 𝑥 𝑑 log 𝑥
(log10 𝑥) = log 10 and 𝑑𝑥 (log 𝑒 𝑥) = log 𝑒.
𝑑𝑥
Now, 𝑦 = log10 𝑥 + log 𝑒 𝑥
log 𝑒 𝑥
= + log 𝑒 𝑥 = log10 𝑒 log 𝑒 𝑥 + log 𝑒 𝑥
log 𝑒 10
𝑑𝑦 log10 𝑒 1
So, 𝑑𝑥
= 𝑥
+𝑥
𝑑 log 𝑥 𝑑 log𝑒 𝑥
But 𝑑𝑥 (log10 𝑥) ≠ log 10
and 𝑑𝑥 (log 𝑒 𝑥) ≠ log 𝑒
.
Therefore, statement 1 is true but statement 2 is false.
56. (d) :
𝜃
Given that, 𝑥 = cos 𝜃 + log tan ( ) and 𝑦 = sin 𝜃.
2
𝑑𝑥 1 𝜃 1
So, 𝑑𝜃
= − sin 𝜃 + tan 𝜃/2 sec 2 2 ∙ 2
𝜃
cos 1 1 1
2
= − sin 𝜃 + 𝜃 𝜃 ∙ 2 = − sin 𝜃 + 𝜃 𝜃
sin cos2 2 sin cos
2 2 2 2
1 1 cos2 𝜃
= − sin 𝜃 + = − sin 𝜃 + =
2𝜃 sin 𝜃 sin 𝜃
sin
2
𝑑𝑦
And 𝑑𝑥
= cos 𝜃
𝑑𝑦 cos 𝜃
Then, 𝑑𝑥
= cos2 𝜃
= tan 𝜃 ⇒ tan 𝜃 = 0
sin 𝜃
𝜃 = 𝑛𝜋, 𝑛𝑒𝑍
57. (d) :
Given that, 𝑦 = (1 − 𝑥)2 (𝑥 − 2)3 (𝑥 − 3)5
⇒ log 𝑦 = log[(1 − 𝑥)2 (𝑥 − 2)3 (𝑥 − 3)5 ]
⇒ log 𝑦 = log(1 − 𝑥)2 + log(𝑥 − 2)3 + log(𝑥 − 3)5
⇒ log 𝑦 = 2 log(𝑥 − 1) + 3 log(𝑥 − 2) + 5 log(𝑥 − 3)
1 𝑑𝑦 2 3 5
So, 𝑦 𝑑𝑥 = 𝑥−1 + 𝑥−2 + 𝑥−3
𝑑𝑦 2 3 5
⇒ = 𝑦[ + + ]
𝑑𝑥 𝑥−1 𝑥−2 𝑥−3
𝑑𝑦 2 3 5
⇒ = (1 − 𝑥)2 (𝑥 − 2)3 (𝑥 − 3)5 [ + + ]
𝑑𝑥 𝑥−1 𝑥−2 𝑥−3
At 𝑥 = 4, we get
𝑑𝑦 2 3 5
(𝑑𝑥 ) = 32 ∙ 23 ∙ 15 [ 3 + 2 + 1 ]
𝑥=4
4 + 9 + 30
= 9 × 8[ ] = 12 × 43 = 516
6
58. (d) :
𝑡2 𝑡
Given that, 𝜃 = 20 + 5
𝑑𝜃 𝑡 1
Then, 𝜔= 𝑑𝑡
= 10 + 5
At 𝑡 = 4, we get 𝜔𝑡=4 = 𝑘
2 1
⇒ + =𝑘
5 5
3
⇒ 𝑘 = ⇒ 5𝑘 = 3
5
59. (c) :
Given that, 𝑦 = 𝛼𝑥 2 − 6𝑥 + 𝛽 (1)
𝑑𝑦
So, 𝑑𝑥
= 2𝛼𝑥 − 6
3
At 𝑥 = 2, the tangent is parallel to 𝑥 − axis. Then,
𝑑𝑦
( ) = 2𝛼𝑥 − 6 = 0
𝑑𝑥 𝑥=3
2
⇒ 3𝛼 − 6 = 0 ⇒ 𝛼 = 2
If point (0, 2) lies on parabola Eq. (1), we get
2=0−0−𝛽 ⇒𝛽 =2
60. (a) :
Given that, 𝑓(𝑥) = 𝑥 2 − 2𝑥
So, 𝑓 ′ (𝑥) = 2𝑥 − 2
Since, 𝑓 ′ (𝑥) < 0
⇒ 2𝑥 − 2 < 0
⇒𝑥<1
Therefore, the given function is strictly decreasing in the interval 𝑥 ∈ (−∞, 1).
BIOLOGY