Selfstudys Com File
Selfstudys Com File
1 1
2 2
1 1
C = 80 F L = 5H 1 2 2 1
R = 40
(a) is longer than and the ratio of the
longer to the shorter wavelength is 1.5
(b) is longer than and the ratio of the
V = 200 V longer to the shorter wavelength is 1.5
(c) and are equal and their ratio is 1.0
(d) is longer than and the ratio of the
25 longer to the shorter wavelength is 2.5
(a) 25 Hz (b) Hz
39. In Young's double slit experiment, the interference
pattern is found to have an intensity ratio
50 between bright and dark fringes is 9. This implies
(c) 50 Hz (d) Hz
the
(a) the intensities at the screen due to two slits
35. If the coefficient of mutual induction of the
are 5 units and 4 units respectively
primary and secondary coils of an induction coil (b) the intensities at the screen due to the two
is 5H and a current of 10A is cut off in 5×10–4 slits are 4 units and 1 units respectively
second, the emf induced(in volt) in the secondary (c) the amplitude ratio is 7
coil is (d) the amplitude ratio is 6
(a) 5×104 (b) 1×105 40. Rising and setting sun appears to be reddish
(c) 25×10 5 (d) 5×106 because
(a) Diffraction sends red rays to earth at these
36. A voltage of peak value 283 V and varying
times
frequency is applied to a series L, C, R
(b) Scattering due to dust particles and air
combination in which R = 3 ohm, L=25 mH and molecules are responsible
C= 400 F. The frequency (in Hz) of the source at (c) Refraction is responsible
which maximum power is dissipated in the above (d) Polarization is responsible
is
(a) 51.5 (b) 50.7 PART - II (CHEMISTRY)
(c) 51.1 (d) 50.3
37. Four independent waves are represented by 41. The catalyst used in Rosenmund reaction is
equations (a) Zn / Hg (b) Pd / BaSO4
(1) X1 = a1sin t (3) X2 = a2sin2 t (c) Raney Ni (d) Na in Ethanol
(2) X3 = a1sin t (4) X4 = a1sin( t+ ) H 2O
42. CH 2 CO 2
O RMgX ?
Interferen ce is possible between waves
represented by equations (a) ROOC(CH2)COOR
(b) RCOCH2CH2COOH
(a) 3 and 4 (b) 1 and 2 (c) RCOOR
(c) 2 and 3 (d) 1 and 4 (d) RCOOH
43. Identify, which of the below does not possess 51. In TeCl4 the central atom tellurium involves
any element of symmetry? (a) sp3 hybridization
(a) (+)– Tartaric acid (b) sp3d hybridization
(b) Carbon tetrachloride (c) sp3d2 hybridization
(c) Methane (d) dsp2 hybridization
(d) Mesotartatric acid 52. The purple colour of KMnO4 is due to the
transition
44. The weakest acid amongst the following is
(a) C.T. (L M) (b) C.T. (M L)
(a) ClCH2COOH (b) HCOOH
(c) d – d (d) p –d
(c) FCH2CH2COOH (d) CH2(I)COOH
53. A nuclear reaction of 235 with a neutron
92 U
45. HOOC CH 2 4 COOH 2C 2 H5OH
H2SO 4 produces 90
36 Kr and two neutrons. Other element
C2 H5OOC CH 2 COOC2 H 5
Toluene produced in this reaction is
The purpose of using toluene here is (a) 137 (b) 144
52Te 55 Cs
(a) to make both substances (acid & alcohol)
miscible (c) 137 (d) 144
56 Ba 56 Ba
(b) that the product is insoluble in toluene 54. AgCl dissolves in a solution of NH3 but not in
(c) that the reactants are insoluble in water water because
(d) because of the formation of low boiling (a) NH3 is a better solvent than H2O
azotrope (b) Ag+ forms a complex ion with NH3
46. Trans esterification is the process of (c) NH3 is a stronger base than H2O
(a) conversion of an aliphatic acid to ester (d) the dipole moment of water is higher than
(b) conversion of an aromatic acid to ester NH3
(c) conversion of one ester to another ester 55. Which of the following is hexadenate ligand?
(d) conversion of an ester into its components (a) Ethylene diamine
namely acid and alcohol (b) Ethylene diamine tetra acetic acid
(c) 1, 10- phenanthroline
47. The correct sequence of base strengths in
(d) Acetyl acetonato
aqueous solution is
56. A coordinate bond is a dative covalent bond.
(a) (CH3)2NH > CH3NH2>(CH3) 3N
Which of the below is true?
(b) (CH3)3N > (CH3)2 NH>CH3NH2 (a) Three atoms form bond by sharing their
(c) (CH3)3N > CH3 NH2= (CH3 )2 NH electrons
(d) (CH3)2N H > (CH3 )3 N> CH3 NH2 (b) Two atoms form bond by sharing their
48. When aqueous solution of benzene electrons
diazoniumchloride is boiled, the product formed (c) Two atoms form bond and one of them
is provides both electrons
(a) C6H5CH2OH (b) C6H6+N2 (d) Two atoms form bond by sharing electrons
(c) C6H5COOH (d) C6H5OH obtained from third atom
49. Carbylamine reaction is given by aliphatic 57. Which of the following complex has zero
(a) primary amine magnetic moment (spin only)?
(b) secondary amine (a) [Ni(NH3 )6 ]Cl2 (b) Na 3[FeF6 ]
(c) tertiary amine (c) [Cr(H 2O)6 ]SO4 (d) K 4 [Fe(CN)6 ]
(d) quaternary ammonium salt
58. The IUPAC name of [Ni(PPh3)2Cl2]2+ is
NH3 (a) bis dichloro (triphenylphosphine) nickel (II)
50. C6 H5 CHO ?
H 2 ,Ni (b) dichloro bis (triphenylphosphine) nickel (II)
(a) C6H5NH2 (b) C6H5NHCH3 (c) dichloro triphenylphosphine nickel (II)
(c) C6H5 CH2NH2 (d) C6H5NHC6H5 (d) triphenyl phosphine nickel (II) dichloride
59. Among the following the compound that is both 67. Given the equilibrium system:
paramagnetic and coloured is NH4Cl (s) NH4+(aq) + Cl–(aq)
(a) K2Cr2O7 (b) (NH4)2 [TiCl6] ( H = +3.5kcal/mol).
(c) VOSO4 (d) K3Cu (CN)4 What change will shift the equilibrium to the
60. On an X-ray diffraction photograph the intensity right?
of the spots depends on (a) Decreasing the temperature
(a) neutron density of the atoms/ions (b) Increasing the temperature
(b) electron density of the atoms/ions (c) Dissolving NaCl crystals in the equilibrium
(c) proton density of the atoms/ions mixture
(d) photon density of the atoms/ions (d) Dissolving NH 4NO 3 crystals in the
equilibrium mixture
61. An ion leaves its regular site occupy a position
68. According to Arrhenius equation, the rate
in the space between the lattice sites is called
constant (k) is related to temperature (T) as
(a) Frenkel defect (b) Schottky defect
(c) Impurity defect (d) Vacancy defect k2 Ea 1 1
(a) In –
62. The 8:8 type of packing is present in k1 R T1 T2
(a) MgF2 (b) CsCl
(c) KCl (d) NaCl k2 Ea 1 1
(b) In – –
63. When a solid melts reversibly k1 R T1 T2
(a) H decreases (b) G increases
(c) E decreases (d) S increases k2 Ea 1 1
(c) In
64. Enthalpy is equal to k1 R T1 T2
G G/T
(a) –T 2 (b) –T 2 In
k2
–
Ea 1 1
T T (d) k1 R T1 T2
V P
G/T
69. Equivalent amounts of H2 and I2 are heated in a
G
(c) T2 (d) T 2 closed vessel till equilibrium is obtained. If 80%
T V T of the hydrogen can be converted to HI, the Kc
P
65. Condition for spontaneity in an isothermal at this temperature is
process is (a) 64 (b) 16
(c) 0.25 (d) 4
(a) A W 0 (b) G U 0
70. For the reaction H2(g)+I2(g) 2HI(g), the
(c) A U 0 (d) G–U 0 equilibrium constant Kp changes with
66. Given: 2C s 2O 2 g 2CO2 g ; (a) total pressure
(b) catalyst
H –787kJ (c) the amount H2 and I2
(d) temperature
1 71. How long (in hours) must a current of 5.0 amperes
H2 g O2 g H 2O( ); H –286kJ
2 be maintained to electroplate 60g of calcium from
molten CaCl2?
1
C2 H 2 g 2 O2 g 2CO 2 g H 2O( ) (a) 27 hours (b) 8.3 hours
2 (c) 11 hours (d) 16 hours
; H –1310kJ 72. For strong electrolytes the plot of molar
The heat of formation of acetylene is conductance vs C is
(a) –1802 kJ (b) +1802 kJ (a) parabolic (b) linear
(c) +237 kJ (d) –800 kJ (c) sinusoidal (d) circular
73. If the molar conductance values of Ca2+ and Cl– 80. In which of the below reaction do we find , -
at infinite dilution are respectively 118.88×10–4 unsaturated carbonyl compounds undergoing
m2 mho mol–1 and 77.33×10–4 m2 mho mol–1 then a ring closure reaction with conjugated dienes?
that of CaCl2 is (in m2 mho mol–1) (a) Perkin reaction
(a) 118.88 × 10–4 (b) 154.66 × 10–4 (b) Diels-Alder reaction
(c) 273.54 × 10–4 (d) 196.21× 10–4
(c) Claisen rearrangement
74. The standard reduction potentials at 298K for
(d) Hoffman reaction
the following half reactions are given against
each
Zn2+ (aq) + 2e– Zn(s) E0 = – 0.762 V PART - III (MATHEMATICS)
Cr3+ (aq) + 3e– Cr(s) E0 = – 0.740 V
2H+ (aq) + 2e– H2(g) E0 = 0.00 V
Fe3+ (aq) + 3e– Fe2+(aq) E0 = + 0.762 V 81. Let the pairs a , b and c , d each determine a
The strongest reducing agent is plane. Then the planes are parallel if
(a) Zn(s) (b) Cr(s)
(c) H2(g) (d) Fe2+(aq) (a) a c b d 0
75. The epoxide ring consists of which of the
following ? (b) a c b d 0
(a) Three membered ring with two carbon and
one oxygen (c) a b c d 0
(b) Four membered ring with three carbon and
one oxygen a b c d 0
(d)
(c) Five membered ring with four carbon and
one oxygen
82. The area of a parallelogram with 3iˆ ˆj – 2kˆ and
(d) Six membered ring with five carbon and
one oxygen ˆi – 3jˆ 4kˆ as diagonals is
76. In the Grignard reaction, which metal forms an
organometallic bond? (a) 72 (b) 73
(a) Sodium (b) Titanium
(c) Magnesium (d) Palladium (c) 74 (d) 75
77. Phenol is less acidic than 83. If cosx + cos2 x=1then the value of
(a) p-chlorophenol sin12 x+ 3sin10 x + 3sin8x + sin 6 x–1 is equal to
(b) p-nitrophenol (a) 2 (b) 1
(c) p-methoxyphenol (c) –1 (d) 0
(d) ethanol
84. The product of all values of (cos +i sin )3/5 is
78. Aldol condensation is given by
equal to
(a) trimethylacetaldehyde
(b) acetaldehyde (a) 1 (b) cos +i sin
(c) benzaldehyde (c) cos3 +i sin3 (d) cos5 +i sin5
(d) formaldehyde 2
79. Give the IUPAC name for 1 i
85. The imaginary part of is
O O i 2i –1
|| ||
H3C CH 2 C H 2 C CH 2 C OCH3 4
(a) (b) 0
(a) Ethyl-4-oxoheptonate 5
(b) Methyl-4-oxoheptonate
(c) Ethyl-4-oxohexonate 2 4
(c) (d) –
(d) Methyl-4-oxohexonate 5 5
u u
86. If sin –1 x sin –1 y , then cos–1x + cos–1y is 93. If (x +y )sin u = x2y2, then x y
2 x y
equal to
(a) sin u (b) cosec u
(a) (b) (c) 2 tan u (d) tan u
2 4
94. The angle between the tangents at those points
3 on the curve x = t2 + 1 and y = t2 – t – 6 where it
(c) (d)
4 meets x-axis is
87. The equation of a directrix of the
4 5
x 2 y2 (a) tan –1 (b) tan –1
ellipse 1 is 29 49
16 25
(a) 3y = 5 (b) y = 5 10 8
(c) 3y = 25 (d) y = 3 (c) tan –1 (d) tan –1
49 29
88. If the normal at (ap2, 2ap) on the parabola
y2 = 4ax, meets the parabola again at (aq2, 2aq),
then 4
(a) p2 + pq + 2 = 0 (b) p2 – pq + 2 = 0 95. The value of x – 3 dx is equal to
(c) q2 + pq + 2 = 0 (d) p2 + pq + 1 = 0 1
89. The length of the straight line x – 3y = 1
intercepted by the hyperbola x2 – 4y2 = 1is 5
(a) 2 (b)
6 2
(a) 10 (b)
5
1 3
(c) (d)
1 6 2 2
(c) (d) 10
10 5 96. The area of the region bounded by the straight
90. The curve described parametrically by lines x = 0 and x = 2 and the curves y = 2x and
x = t2 + 2t–1, y = 3t + 5 represents y = 2x –x2 is equal to
(a) an ellipse (b) a hyperbola
(c) a parabola (d) a circle 2 4 3 4
91. If the normal to the curve y = f(x) at (3,4) makes (a) – (b) –
log 2 3 log 2 3
3
an angle with the positive x-axis, then f '(3)
4 1 4 4 3
(c) – (d) –
is equal to log 2 3 log 2 2
3
(a) – 1 (b)
4 dx
97. The value of 7
is equal to
3 0 a2 x2
(c) 1 (d) –
4
92. The function f(x) = x2 e–2x, x > 0. Then the
maximum value of f(x) is 231 1 235 1
(a) (b)
1 1 2047 a13 2048 a13
(a) (b)
e 2e
232 1 231 1
1 4 (c) (d)
(c) (d) 2047 a13 2048 a13
e2 e4
101. The general solution of the differential equation
2
x 1– x d2 y dy
98. The value of the integral e 2
dx is 2 y 2e3x is given by
1 x dx 2 dx
e3x
ex
1– x
C (a) y c1 c 2 x e x
(a) 8
1 x2
e –3x
(b) y c1 c 2 x e – x
1 x 8
(b) ex C
1 x2 e3x
(c) y c1 c2 x e – x
8
ex e –3x
(c) C y c1 c2 x e x
1 x 2 (d)
8
(d) ex(1–x) + C 102. The solution of the differential equation
ydx+(x–y3)dy = 0 is
y y 1 3
99. If x sin dy y sin – x dx (a) xy y C (b) xy = y4 + C
x x 3
(c) y4 = 4xy + C (d) 4y = y3 + C
103. The number of positive integral solutions of the
y equation x1 x2x3x4x5=1050 is
and y 1 , then the value of cos is
2 x (a) 1870 (b) 1875
(c) 1865 (d) 1880
equal to 104. Let A= {1,2,3,....., n}and B ={a,b,c}, then the
number of functions from A to B that are onto is
1 (a) 3n – 2n (b) 3n – 2n –1
(a) x (b) n
x (c) 3 (2 – 1) (d) 3n – 3(2n – 1)
105. Everybody in a room shakes hands with
(c) log x (d) ex everybody else. The total number of hand
100. The differential equation of the system of all shakes is 66. The total number of persons in the
room is
circles of radius r in the XY plane is (a) 9 (b) 12
(c) 10 (d) 14
2 2
dy
3
d2 y 106. If(G,*) is a group and the order of an element
(a) 1 r2 a G is 10, then the order of the inverse of a* a
dx dx 2 is
1
(a) 10 (b)
3 2 3 10
dy 2 d2 y
(b) 1 r 1
dx dx 2 (c) 5 (d)
5
107. A box contains 9 tickets numbered 1 to 9
inclusive. If 3 tickets are drawn from the box one
2 3 2
dy 2 d2 y at a time, the probability that they are
(c) 1 r alternatively either {odd, even, odd} or {even,
dx dx 2 odd, even} is
5 4
(a) (b)
2 3 3 17 17
dy d2 y
(d) 1 r2 5 5
dx dx 2 (c) (d)
16 18
1 5 1 –1 2 5
108. If P(A) = , P(B) = and P(B/A)= then
12 12 15 114. If the rank of the matrix 2 –4 a – 4 is 1,
p A B is equal to 1 –2 a 1
(a) A( ) (b) A PQ
2 (a) 2 (b)
P Q
– 1 P Q
(c) A(– ) (d) A (c) (d)
2 2 PQ
PART - I (PHYSICS) 3 3 36
2 Rc f 1.35f .
16 16 5
1. (d) The magnetic moment of the ground state 5. (d) Here, Kinetic energy = Rest energy
of an atom whose open sub-shell is half we know that
filled with n electrons is given by Kinetic energy (Relativistic)
= (m – m0)c2,
n(n 2). B and Rest energy = m0c2,
where B is the gyromagnetic moment of where m0 = rest mass, c = velocity of light
the atom. Also, mass (m) of a particle moving with
Here, n = 5. velocity v is given by
5(5 2). B 35 B m0
m .
2. (a) Bragg's law gives 2dsin = n , n= order of v2
reflection, d= distance between planes. For 1
c2
same and d, n for a given , smallest
d for least n, can be found. If crystal is (m – m0)c2 = m0c2 provides
symmetric reflections from different planes
may cancel out.
3. (b) According to Moseley's law, square root
of frequency of X-ray is plotted against m0
m0 c 2 m 0c2
atomic number it gives straight line, the v 2
relation is 1
c2
f c Z – 1 where c = constant
1
(for f 0, Z c , for Z = 0, f –c ) or, 1 1
Option (b) is correct. as Z can not be v2
1
negative. c2
4. (b) Balmer series is given for n 1 = 2 and
n2 = 3, 4, ... v2 1
1 1
or, 2 or, 2
1 1 c 4
Rc – v2
1
22 n 22 c2
For Ist line in spectrum n2 = 3
v2 1 3
or, 2
1
1 1 1 1 c 4 4
1 Rc – Rc – f
2 2 4 9
2 n2 3
v c.
5 36 2
f Rc Rc f
36 5 v2 1
1– 2
=
For second line n 2 = 4 c 4
1 1 1 1 v2 1 3 3 2
Rc – Rc –
2
2 2
4 2 4 16 2 =1 = v2 = c
c 4 4 4
4 –1 3
Rc v= c
16 2
6. (d) de-Broglie wavelength ( ) of a particle of 10. (c) Radio carbon dating is done by measuring
mass m and moving with a velocity v is ratio of 14C present in the sample, since
proportion of 14C and 12 C in a body is same;
h
given by, , where h is Planck's but after death 14C decays. Hence knowing
mv the present ratio of 14C to 12 C, sample can
constant. be dated.
When a particle having charge q is 11. (b) particles are positively charged He
accelerated through a potential V then nucleus, it can accept 2e– , rays are
1 negatively charged which are similar to e–,
qV mv 2 can donate 1e–, are radiations. Hence
2
ionisation power of is maximum. are
m 2 v2 most energetic and is least energetic
or, qV mv 2mqV Penetration power of is maximum
2m
12. (d) Given half life T= 3.8 days; t = 19 days
h N t 19
2mqV ? now 5
N0 T 3.8
Hence, de-Broglie wavelength of electron,
t
5
h N 1 T 1 1
e
2me eV N0 2 2 32
8.93
2 C = 100 pF = 100 × 10–12 F, = 8.85 × 10–12,
Modulation index, m a –1 2 A = r2 = 3.14×(10–2)2 (r = lcm)
82
t = 10–3m, d = t, K = 4
79.7
–1 2 1.24 –1 2
64 8.85 10 –12 3.14 10 –4
C1
= 0.701 1
10 –3 –10 –3 (1 – )
Percentage modulation = ma × 100 =70.1% 4
1
21. (d) For a point charge, E . For positive 27.79 10 –16
x2
10 –3 – 0.75 10 –3
charges, electric field will decrease in
positive direction as distance increases,
27.79 10 –13
(case 1), for negative charge, as distance
increases field will increase (case 4). As we 0.25
move from positive charge to negative
charge, field will keep on decreasing (case 27.79 10 –13
111.16 10 –13 F
2), As we move from negative to positive 0.25
charge, field will keep on increasing (case 3) (for 1 set)
A 4 cm B(q 1) Required C = 100 10 –12
F
22. (a) 3 cm 3 cm
C 100 10 –12
n 10
D(q 3 ) 4 cm C(q 2) C1 111.16 10 –13
24. (a) The resultant intensity at a point on 26. (c) Since conductor and semiconductor are
connected in parallel hence voltage across
equatorial line is E . E is parallel and them is same. If ammeters show same
opposite to direction of p . V
reading hence their resistances R are
I
E2 same. If voltage is increased by small value
E 3 cm
then following the same relation V I for
E1 constant R, both conductor and
semiconductor show same current.
27. (d) Time taken by free electrons to cross the
–q +p
O conductor
I
25. (d) Let a total current of 6I enter at A. It divides t where drift velocity v d
vd neA
into three equal parts, each of 2I, along AE,
AB and AD. At E, B and D each the current
1
2I divides into two equal parts, each of I, vd 28
along EF, EH, BF, BC, DH and DC. 8 10 1.6 10 –19 5 10 –7
At F, H and C, the two currents each of I, 10 –2
combine together to give a current of 2I at m/s .
64
each corner. Thus, at G we get the same
1 64
current 6I as shown in the figure. t 64 102 s 6.4 103 sec
vd 10–2
E I F
2I
R 2 – R1
I I 28. (b) Temperature coefficient,
A B 2I R1 t 2 – t1
2I I 2I G 6I
2I H
R 2 – R1
6I
I 2I t 2 – t1
D I C R1
2 –1
E t 2 – t1
1 0.00125
Let r be the value of resistance of each arm 1
of the cube and R be the joint resistance t2 t1 800 300 1100K
0.00125
across the conners A and G.
29. (d) Torque on the coil is = nIB A cos . If coil
Applying Kirchhoff's law along the loop is set with its plane parallel to direction of
AEFGA, we get magnetic field B, then =0°, cos = 1
2Ir + Ir + 2Ir = E = nIBA.1 = nIBA = maximum.
or, 5Ir = E ........... (1) Hence, I = maximum (as n,B, A are constant)
Also, by Ohm's law, 1 2
6I × R = E 30. (d) E at
bt is the parabolic equation for
2
6IR = 5Ir, using (1) thermo emf. The thermoelectric power is
5 dE
or, R r. S
6 dt
Here, r = 6 dE
S = a + bt. The graph between S
5 dt
R 6 5
6 and straight line.
When t = 0, S = a (intercept).
1 1
dE –6
At neutral temperature 0 and 2 5 80 10 2 400 10 –6
dt
1
–a
t = tn 0 = a + btn tn and at cold 2 20 10 –3
b
= ˆi(4 6) ˆj (12 2) kˆ ( 9 1) 55 33 22
i isin
sin 2.2. 55 11 ..
22 55 55
d1 × d 2 = 2iˆ 14ˆj 10kˆ
5 6 8 5 6 8
d1 d 2 = ( 2) 2 ( 14) 2 ( 10) 2 = cos . i sin
2 5 5 2 5 5
= 4 196 100 300 2 75
5 6 2 5 6 8
1 cos . i sin
Area of parallelogram = d1 d 2 2 5 5 2 5 5
2
= cos (3 + 4 ) + i sin(3 + 4 )
1 = cos (4 + 3 ) + i sin (4 + 3 )
= × 2 75 = 75 square units
2 = cos 3 + i sin 3
2
1 i 1 i2 2i
85. (d) 2 Y
i 2i 1 2i i y= a/e
directrix
1 1 2i 2i 2 i 4i 2i 2 4i 2 2 4i (0,5)
2 i 2 i 2 i 4 i2 4 1 5
[ i2 = –1]
F (0,c)
(–4,0) (4,0)
2i 2i 4i 2i 2 4i 2 2 4i 2 4i X
2 1 2 i 4 i 2 4 1 5 5 5 X'
F' (0, – c)
4
The imaginary part = –
5 (0,–5) y= – a/e
5 2 2
13 6
y= 3y = ± 25 PQ = 1 0
3/ 5 5 5
2 U U sin U
18 36 x y tan U
324 36 360 x y cos U
5 25
25 25 U U
x y tan U
6 10 x y
length of straight line PQ = units.
5 94. (c) Equation of the given curve in parametric
90. (c) Given x = t2 + 2t–1 & y = 3t + 5 form,
x = t2 + 1 and y = t2 – t – 6
x = t2 + 2t + 1–2 & y = 3t + 3+2
Y-coordinate of the point, where the given
x = (t+1)2 –2 & y = 3(t + 1) + 2 (2)
curve meets X-axis is 0.
(t+1) = x 2 .......... (1) When y = 0, then t2 – t – 6 = 0
Equation (2) becomes [using equation (1)] t 2 3t 2t 6 0
y= 3 x 2 2 t(t 3) 2(t 3) 0
y–2 = 3 x 2 (t 3)(t 2) 0
squaring both sides, we get t 3 or 2
(y–2)2 = 9 (x + 2)
when t = 3, then x = 10
Y2 =9X where Y = y – 2 & X = x + 2
when t = –2, then x = 5
This equation represents a parabola Hence, the points where the curve meets
91. (c) Slope of the normal at (3,4) is the value of the X-axis are (10, 0) and (5, 0).
1 1 3 dy
at x = 3 or = tan =–1
f '(x) f '(3) 4 dy dt 2t 1
f`'(3) = 1 Now, dx dx 2t
92. (c) Given : f (x) = x2 e–2x, x > 0 dt
f '(x) = x2.e–2x(–2) + e–2x.2x Slope of the tangent at point (10, 0)
put f '(x) = 0 2e–2x. x (–x + 1) = 0 dy dy 5
x = 1 or x = 0 m1
dx x 10 dx t 3 6
f"(x) = (–4x2 – 6x + 1)e–2x
f"(1) = –9e–2x < 0 Slope of the tangent at point (5, 0),
f"(0) = e–2x > 0 dy dy 5 5
value of f(x) is maximum at x = 1 m2
dx x 5 dx t 2 4 4
1 If be the angle beween two tangents, then
f(x) = x2.e–2x f(1) = e–2 = 2
e 55
93. (d) Given : (x + y) sin U = x2y2 m 2 m1 64
tan
1 m1m 2 5 5
x 2 y2 1
sinU = = v (let) 6 4
x y
Here n = 2 – 1 = 1 15 10 5
12 12 10
v v
Euler's theorem x. y. nv 24 25 49 49
x y
24 24
sin U sin U 10
x y sin U tan
x y 49
U U 1 10 1 10
x.cos U y.cos U. sin U tan tan
x y 49 49
4 3 4
dx
95. (b) | x 3 | dx (x 3)dx (x 3)dx 97. (d) Let I 2
1 1 3 0 (a x 2 )7
x2
3
x2
4
Put x a tan dx a sec2 d
3x 3x
2 2
1 3
limit at x 0 0&x
2
1 2 2 1 2 2
[3 1 ] 3[3 1] .[4 3 ] 3[4 3]
2 2
1 1
2
a sec 2
(8) 3(2) .(7) 3(1) I d
2 2 0 a14 (1 tan 2 )7
7 5
4 6 3
2 2
2 2
1 1 1
2 d . cos12 .d
96. (b) Required area (y 2 y1 )dx a13 0 sec12 a13 0
0
But
y 2 1
x
y=2 (2,4) sin 2m 1 .cos 2n 1 . d B(m, n)
2
(x2y2) 0
(0,1) Q
(1,1) m n 1
& B(m, n) &
m n 2
P
2
1
x' I sin 0 . cos12 d
o
x a13 0
(2,0)
2
–x
2x
1 13
m , n
y=
2 2
1 13
.
1 2 2
2
I
x 2 2a13 1 13
(2 2x x )dx
2 2
0
2 11 9 7 5 3 1
2x x3 . . . . . . .
1
x2 . 2 2 2 2 2 2
log 2 3 2a13 6.5.4.3.2.1
0
4 8 1 3 4 231 1
4 .
log 2 3 log 2 log 2 3 2048 a13
(1 x)2
98. (c) Let I ex dx cos log(1) c c 0
(1 x 2 )2 2
y
x 1 x 2 2x cos log x
I e dx x
(1 x 2 )2 100. (c) The equation of the family of circles of
radius r is
1 x2 2x (x – a)2 + (y – b)2 = r2 ...(1)
ex dx
2 2
(1 x ) (1 x 2 )2 Where a & b are arbitrary constants.
Since equation (1) contains two arbitrary
1 x constants, we differentiate it two times w.r.t
I ex dx 2 e x . dx
(1 x 2 ) (1 x 2 )2 x & the differential equation will be of
second order.
1 Differentiating (1) w.r.t. x, we get
I .e x ex . (1 x 2 ) 2 2xdx
(1 x 2 )
dy
2(x a) 2(y b) 0
ex x dx
2 dx
(1 x 2 )2 dy
(x a) (y b) 0 ...(2)
ex x dx
ex dx
I 2 Differentiating (2) w.r.t. x, we get
1 x2 (1 x 2 )2
2
d2 y dy
ex x 1 (y b) 0 ...(3)
2
2 2
dx dx 2 dx
(1 x )
2
x dy
e 1
I +C dx
1 x2 (y b)
d2 y ...(4)
y y dx 2
99. (c) Given : x sin dy y sin x dx
x x On putting the value of (y – b) in equation
(2), we get
y
y sin x
dy x dy
2
dy
dx y 1
x sin dx dx
x x a
d2 y ...(5)
y dy dz dx 2
Put z z.1 x.
x dx dx Substituting the values of (x – a) & (x – b)
dz zx sin z x in (1), we get
x. z z cosec z
dx x sin z
2 2 2 2 2
dy dy dy
dz dx 1 1
x cosec z sin z dz dx dx dx
dx x r2
2 2
cos z log x c d2 y d2 y
2
y dx dx 2
cos log x c
x
2 3 2
dy 2 d2 y
1 r
But y(1) x 1, y dx dx 2
2 2
104. (d) Number of onto functions: If A & B are two
d2 y dy 3x sets having m & n elements respectively
101. (c) Given : 2 y 2e
dx 2 dx such that 1 n m then number of onto
The auxiliary equation is functions from A to B is
D2 + 2D + 1 = 0 or m2 + 2m + 1 = 0 n
n r n
(m 1)(m 1) 0 m 1, 1 –1 . Cr r n
r 1
i.e., repeated roots
Given A = {1, 2, 3, ---- n} & B = {a, b, c}
Complementary function = (c1 + c2x)e–x Number of onto fun ction s
Now Particular Integral (P.I.)
3
3–r 3 n
1 –1 . Cr r
. 2e3x [D = 3] r 1
D2 2D 1
3 13 n 3 2 3 n
1 C1 1 –1 C2 2
1 3x 2e3x e3x
P.I. . 2.e
32 2.3 1 16 8 3
C3 3
n
–1
3 3
Solution y = C. F. + P. I.
3 3
C1 C2 2n 3
C3 3n
3x
e
y c1 c2 x e – x 3! 3! n 3! n
8 2 3
2!1! 2!1! 3! 0!
102. (c) Given ydx + (x – y3) dy = 0
dx dx 1 3 3. 2n 3n
y x y3 0 x y2
dy dy y
3n 3 2n 1
compare this equation to general equation
105. (b) Let there are n persons in the room. The
dx 1 2 total number of hand shakes is same as the
i.e. Px Q P ,Q y
dy y number of ways of selecting 2 out of n.
1 n n n 1
Pdy
dy C2 66 66
I.f . e e y
e log y
y 2!
1 P A B 1 1 tan
B 2
.
15 1/12 sec tan 1
1 1
P A B 1
15 12 180 B .A
sec2
But,
P A B P A P B P A B sec 2 .B A
1 5 1 89 1
P A B cos 2 .B A
12 12 180 180
2 x
109. (a) f x dx , where f x 112. (b) Given : 2x 1 4 8
1.5 2
2 2x 2 0
2
2 x 1 2 1 x 2 7 6 2x
dx . xdx
1.5 2 2 1.5 2 2
1.5
2x 1 4x 2 12 4 4x 14
1 1 175 7
4 2.25 1.75
4 4 400 16 8 12 14x 0
110. (b) If 2 P(X = 0 ) + P (X = 2) = 2 P (X = 1)
Let probability distribution of X be given 8x 3 24x 4x 2 12 16x
by 56 96 112 x 0
r m
m .e 8x 3 4x 2 152x 140 0
P(X = r) where r = 0, 1, 2, .....
r! (x + 5) is a factor of above equation
m0 e m m2 .e m
m.e m
8x 3 40x 2 36x 2 180x
2 2
0! 2! 1!
28x 140 0
2
m2 8x x 5 36x x 5 28 x 5 0
2 2m m2 4m 4 0
2
x 5 8x 2 36x 28 0
2
m 2 0 m 2
x 5 4 2x 2 9x 7 0
1 tan
111. (c) A & AB I
tan 1
4 x 5 2x 2 7x 2x 7 0
1
B I A , A11 1, A12 tan ,
4 x 5 x 2x 7 1 2x 7 0
A 21 tan , A 22 1
4 x 5 2x 7 x 1 0
1 tan 2 2
|A| 1 tan sec x 5, 3.5,1
tan 1
113. (b) For only one solution | A | 0 118. (a) Given : H is the harmonic mean between
P&Q
k 2 1
2PQ 1 P Q
0 k 1 2 0 H
P Q H 2PQ
0 0 k 2
2 1 1 H H
k k 1 k 2 0 2
H Q P P Q
k 0, k 1, k 2. k 1
119. (c) We have a b a b
114. (c) Let
1 2 5 1 2 5 a a b b a b
A 2 4 a 4 0 0 a 6
1 2 a 1 0 0 a 6 a .b a a .a b b.b a b.a b
R2 R2 2R1 , R 3 R 3 R1 a .b a b
clearly rank of A is 1 if a = –6
2 2
115. (c) Given : ax 4 bx 2 c 0 a b b.b b 1, a .a a 1
3
a1a 2 b1b 2 c1c 2
1 1 cos
117. (a) x x 0 a12 b12 c1 . a 2 2 b 2 2
2
c22
x x
2
1 2 2 3 4 3
1 1 cos
x x 1 0 1 4 16 . 4 9 9
x x
2 6 12 20
1
x 0 x2 1 0 x i 21 . 22 462
x
Thus, the given equation has no real roots. 462 cos 20