Solution
Solution
1001CJA101001250011 JA
PART-1 : PHYSICS
SECTION-I (i)
1) If a portion of uniform disc of radius 3R is removed and placed near its surface as shown, find x-
(A) 2
(B) 4
(C) 6
(D) 8
2) In the figure shown the initial velocity of boat (30 kg) + person (15 kg) is 2 m/s. Find velocity of
person w.r.t. boat so that velocity of boat will be 1 m/s in right. (Neglect friction between boat and
water)
3) A block of mass 1 kg is resting on a rough horizontal surface with coefficient of friction 0.2. If an
impulse N-s is given to block then the distance travelled by the block till it stops (after
the impulse) is :
(A) 10 m
(B) 0 m
(C) 16 m
(D) 4 m
4) Find moment of inertia of a wire frame about an axis passing through point O & perpendicular to
plane of frame. (linear mass density of wire is 2 kg/m & its radius is 1m)
(A) 2π kg m2
(B)
(C) π kg m2
(D) (π + 1.5) kg m2
SECTION-I (ii)
1) In figure a block A of mass 2 kg is moving to the right with a speed 5 m/s on a horizontal
frictionless surface. Another block B of mass 3 kg with a massless spring of spring constant 120N/m
attached to it, is moving to the left on the same surface and with a speed 2 m/s. Let us take the
direction to the right as the positive X-direction. At some instant, block A collides with the spring
attached to block B. At some other instant, the spring has maximum compression and then, finally,
(A) During the collision the momentum as well as mechanical energy of the system is conserved.
(B) When block A has a velocity of 4m/s in the positive x direction, the velocity of B is m/s in the
negative x direction.
(C) At the maximum compression, the blocks have a common speed of 0.8 m/s in positive direction.
(D) The maximum compression in the spring is 0.7 m.
2) If 3 point masses 1, 2, & 3 kg are rigidly fixed on a massless triangular frame and placed on
smooth frictionless table as shown below then choose correct statement base on given information.
(A) Acceleration of 3 kg must be m/s2.
(B) Acceleration of 2 kg must be m/s2.
(C) Acceleration of 1 kg must be m/s2.
(D) Acceleration of COM must be m/s2.
SECTION-II (i)
1) Maximum speed of 3 kg block in the subsequent motion will be n × v0, find the value of n.
2) The maximum energy stored in the spring in the subsequent motion will be n × , find the value
of n.
3)
What is flight time (in sec) of the shell before it strikes the balloon?
SECTION-II (ii)
1) In the shown arrangement all surfaces are smooth and system is released from rest. Mass of block
A and B are equal (m = 1kg), mass of block C is M = 3kg. After releasing from rest block B strikes
with the surfaces of C after travelling height h = 10 cm. Find the displacement (in cm) of the block
2) One end of a pendulum is attached to point O on the wedge of mass M = 4m. Mass of the
pendulum is m and its length is ℓ. Initially system is at rest on a smooth floor, now velocity v0 = 12
m/s is given to the pendulum in horizontal direction. v0 is sufficient for the bob to move in circle with
respect to O. If at highest point of the trajectory speed of bob is equal to speed of wedge then find
3) A uniform rod of mass 120kg is at angle ϕ = 60° from horizontal. It is supported by a cable at an
angle 30° from horizontal. The rod is pivoted at the bottom and object of mass m = 200kg hangs
from it's top. If tension in the support cable is T, find (in SI unit). Consider system to be in
equilibrium.
4) Two masses m and m, that start simultaneously from the inter-section of two straight lines with
velocities 3 m/s and 4 m/s respectively on a horizontal surface as shown. Find the two times of
5) Spring is at natural length when force F1 and F2 start acting on the mass m1 and m2. If the
maximum elongation of spring during subsequent motion is x (in meter), fill the value of 5x . [m1 =
6) Find value of x if torque of force applied at point (x, 1, –1) about origin is
.
PART-2 : CHEMISTRY
SECTION-I (i)
1) Element A has successive ionization energies 8.2, 16.4, 102.5, 122.4 (in eV/atom). Element B has
corresponding values 10.4, 19.2, 35.6, 49.2, 166.5, 208.7 (eV/atom)
What would be the likely formula for a compound that may be formed from A and B
(A) A4B3
(B) A2B
(C) AB2
(D) A2B3
2)
Among these compounds, the correct order of C – N bond lengths is :
3)
Correct order of bond strength between carbon and oxygen is-
4) A mixture of FeO and Fe2O3 is reacted with acidified KMnO4 (0.2 M) whose 100 ml was used. The
solution was then titrated with zinc dust which converted Fe+3 in solution to Fe+2. In final solution
Fe+2 required 1000 ml, 0.1 M K2Cr2O7 solution for end point. Find millimoles of FeO & Fe2O3 in
original mixture respectively.
SECTION-I (ii)
(A) In Moseley's equation, square root of frequency is directly proportional to atomic number
(B) Silver and gold have nearly same atomic radius
(C) Sc <Y< La (correct order of atomic size)
(D) Atomic number of mercury (Hg) is 80
(A)
> > >
(B)
SECTION-II (i)
1) Find total number of hyperconjugative structure (involving C–H bond) for the following
carbocation.
2) , ,
Find out number of α-hydrogens in alkene among the following which release maximum heat of
hydrogenation on adding H2.
4) 37.5 g Ba(MnO4)2 (mol. wt. = 375) sample containing some inert impurities in acidic medium is
completely reacted with 125 mL of "34.05 V" of H2O2. What is the percentage purity of the sample ?
SECTION-II (ii)
2)
How many of the total number of processes given below are endothermic?
(i) (ii)
(iii) (iv)
(v) (vi)
(vii) (viii)
(ix)
4) A sample of iron weighing 20 g was heated with KClO3(s) in an evacuated container. The oxygen
generated from decomposition of KClO3 converted some of Fe to Fe2O3. If the combined mass of
Fe and Fe2O3 was 21.5 g. Calculated mass of Fe2O3 (in g) formed. (Atomic mass of Fe = 56)
5)
N2O4 dissociates into NO2, if % dissociation of N2O4 is 33.33 %. Calculate average molecular weight
of gaseous mixture formed .
6) How many compounds react with NaHCO3 and release CO2 gas ?
(i) Picric acid (ii) Squaric acid
(iii) Carbolic acid (Phenol) (iv) Acetic acid
(v) Formic acid (vi) Maleic acid
PART-3 : MATHEMATICS
SECTION-I (i)
(A) (1, 1)
(B) (1, –2)
(C) (–1, 2)
(D) (–1, 1)
2) A ray of light is sent along the line x – 2y + 5 = 0. Upon reaching the line 3x + 2y + 7 = 0, the ray
is reflected from it. Then the equation of the line containing the reflected ray is
4) A variable line L passes through the point (3, 5) and intersects the positive coordinate axes at the
points A and B. The minimum area of the triangle OAB, where O is the origin, is :
(A) 30
(B) 25
(C) 40
(D) 35
SECTION-I (ii)
(A)
(B)
(C)
(D)
(A) is consistent
(B) has unique solution
(C) has a solution (x0, y0, z0) such that x0y0z0 > 0
(D) has some non-trivial solution
SECTION-II (i)
Common Content for Question No. 1 to 2
In triangle ABC given that A(2, 1), median through vertex B is y = x & altitude through vertex C is 2x
+ y = 1.
2) If (α, α2) lie inside the triangle ABC, then largest interval in which α lie is (a, b) then value of (a +
b) is :
SECTION-II (ii)
1) A rod of unit length slides along co-ordinate axes such that its two ends A and B always lie on
positive X and Y axes respectively. Then, the locus of a point P (lying in the first quadrant) such that
2) The radius of the circle touching incircle of an equilateral triangle of circumradius 6 unit,
externally and its two sides, is
is
4) Let N be the number of triplets (α, β, γ) where α, β, γ ∈ [0, 2π] satisfying the inequality (4 +
6) Let A(–2, –1), B(1, 0), C(α, β) and D(γ, δ) be the vertices of a parallelogram ABCD. If the point C
lies on 2x – y = 5 and the point D lies on 3x – 2y = 6, then the value of |α + β + γ + δ| is equal to
ANSWER KEYS
PART-1 : PHYSICS
SECTION-I (i)
Q. 1 2 3 4
A. A A C B
SECTION-I (ii)
Q. 5 6 7
A. A,B,C,D D A,C,D
SECTION-II (i)
Q. 8 9 10 11
A. 3.00 15.00 5.00 1075.00
SECTION-II (ii)
Q. 12 13 14 15 16 17
A. 2 4 40 5 8 2
PART-2 : CHEMISTRY
SECTION-I (i)
Q. 18 19 20 21
A. B C A B
SECTION-I (ii)
Q. 22 23 24
A. A,B,C,D A,B,C A,B,D
SECTION-II (i)
Q. 25 26 27 28
A. 4.00 4.00 3.40 75.00
SECTION-II (ii)
Q. 29 30 31 32 33 34
A. 4 7 1 5 69 5
PART-3 : MATHEMATICS
SECTION-I (i)
Q. 35 36 37 38
A. D A D A
SECTION-I (ii)
Q. 39 40 41
A. B,D A,B,C,D A,B
SECTION-II (i)
Q. 42 43 44 45
A. 2.50 1.50 5.00 4.50
SECTION-II (ii)
Q. 46 47 48 49 50 51
A. 4 1 5 8 7 32
SOLUTIONS
PART-1 : PHYSICS
scom =
scom = {s2 = 0}
scom =
2)
3) Ndt = 10 Ns
fdt = µ Ndt = 0.2 × 10 = 2Ns
10 – 2 = 1v
⇒ v = 8 m/s
s = 16 m
I2(Rod) =
6)
Fexternal = m × acom
7)
Theoretical question
8) Velocity of centre of mass is v0 towards left and both the blocks 2kg & 3 kg will perform
simple harmonic motion with speed at mean position 3v0 and 2v0 respectively. So, maximum
speed of 2 kg block will be 3v0 + v0 = 4v0 and maximum speed of 3 kg block will be 2v0 + v0 =
3v0.
9) Maximum energy will be stored in the spring when blocks will be moving with same
velocity.
towards left
So, =
10)
along x direction
11)
= 1075 m
12)
Displacement of mass A is 10 cm
m × 10 = (m + m + 3m) × x
10m = 5xm
x = 2cm
13)
V= = 4 m/s
14)
T = (30g + 100g)
15)
So,
aCM =
(F1)cm =
(F1)cmx1 + (F2)cmx2 =
17) τ = r × F =
PART-2 : CHEMISTRY
18)
Ans is (B)
A ⇢ 8.2, 16.4 , 102.5, 122.4 …….
Valence e– = 2
B ⇢ 10.4, 19.2 , 35.6, 49.2, 166.5, 208.7
Valence e– = 4
∴ Formula is A2B1
19)
III > II > I > IV
22)
24)
CO + CH4 + N2 = 20
x y z
CO + O2 → CO2
x x/2 x
CH4 + 2O2 → CO2 + 2H2O(ℓ)
y 2y y
Volume reduction due to
Reaction =
+ 2y = 13 ....... (i)
x + y = 14 ...... (ii)
y = 4 ml
x = 10 ml
z = 6 ml.
25)
26)
This alkene is least stable and release maximum heat of hydrogenation.
27) Strength in percentage mean how many g H2O2 present per 100 mL
∵ M ⇒ 1 and mol. wt. of H2O2 = 34
∴ 34 H2O2 present per litre of solution or 3.4 H2O2 present per 100 mL of solution.
% purity = = = 75
29)
30)
31)
O2 is L.R.
33) Meff =
1 + 1/3 =
Mav = 69
PART-3 : MATHEMATICS
35)
⇒
⇒
⇒
∴ family passes through (–1, 1)
36)
First we will find the intersection points of these two lines,
x – 2y + 5 = 0 ...(1)
3x + 2y + 7 = 0 ...(2)
from eqn (1) & eqn (2)
⇒
by taking ⊕ sign by taking –ve sign →
37)
cos2x = 1 ⇒ x = nπ, n ∈ I
38)
⇒ ,a>3
39)
= (cosy + cos3y)2 + (siny – sin3y)2
⇒ 2 = cos2y + 2cos4y + cos6y + sin2y + sin6y – 2sin4y
= 1 + 2(cos2y – sin2y) + (cos6y + sin6y)
= 1 + 2(cos2y – sin2y) + cos4y + sin4y – cos2y.sin2y
= 1 + 2(cos2y – sin2y) + (cos2y + sin2y)2 – 3cos2y.sin2y
⇒ 0 = 2 – 4sin2y – 3(1 – sin2y)sin2y
= 2 – 4sin2y – 3sin2y + 3sin4y
⇒ 3sin4y – 7sin2y + 2 = 0
⇒ sin2y =
40)
4x + 3y – 7 = 0
24x + 7y – 31 = 0
a1a2 + b1b2 > 0
obtuse angle bisector
20x + 15y – 35 = 24x + 7y – 31
4x – 8y + 4 = 0 ⇒ x – 2y + 1 = 0
acute angle bisector
20x + 15y – 35 + 24x + 7y – 31 = 0
44x + 22y – 66 = 0
2x + y – 3 = 0
for origin L1 < 0 L2 < 0
same sign so origin lies in x – 2y + 1 = 0
for point (1, –2) L1 < 0 L2 < 0
so same sign so point (1, –2) lies in x – 2y + 1 = 0
41)
42)
Line perpendicular to CN is x – 2y = λ satisfy (2, 1) ⇒ λ = 0
∴ equation of line AB is x = 2y ⇒ B(0, 0)
midpoint of A and C lie on line
y = x ⇒ α = 0 ⇒ C(0, 1)
therefore ABC is right angle triangle whose 90° at vertex C. (α, α2) lie inside the triangle
⇒ α > 0, α2 < 1 and 2α2 – α > 0
⇒ <α<1
43)
Line perpendicular to CN is x – 2y = λ satisfy (2, 1) ⇒ λ = 0
∴ equation of line AB is x = 2y ⇒ B(0, 0)
midpoint of A and C lie on line
y = x ⇒ α = 0 ⇒ C(0, 1)
therefore ABC is right angle triangle whose 90° at vertex C. (α, α2) lie inside the triangle
⇒ α > 0, α2 < 1 and 2α2 – α > 0
⇒ <α<1
44)
Equation of line HB :
⇒ 2y + x = 7 ...(1)
On solving with equation of line AB :
Co-ordinate of B ≡
Similarly co-ordinates of C ≡
⇒ Equation of L :
45)
46)
D≡
Also,
Now, ...(i)
and ...(ii)
solving (i) and (ii) for sinθ and cosθ
and
Hence,
47)
Now,
⇒ r = 3r1 ⇒ 4R × = 3r1
⇒ r1 = 1
48)
α3 + 2α2 – α + 3 = 0
⇒ α3 + α2 + 3 = α – α2 = α(1 – α)
= = (1 – α)(1 – β)(1 – γ)
3 2
Now x + 2x – x + 3 = (x – α)(x – β)(x – γ)
put (x = 1) ⇒ 1 + 2 – 1 + 3 = (1 – α)(1 – β)(1 – γ)
So (1 – α)(1 – β)(1 – γ) = 5
49)
50)
51)
and
⇒α–γ=3 ...(1)
β–δ=1 ...(2)
Also, (γ, δ) lies on 3x – 2y = 6
3γ – 2δ = 6 ...(3)
and (α, β) lies on 2x – y = 5
⇒ 2α – β = 5 ...(4)
Solving (1), (2), (3), (4)
α = –3, β = –11, γ = –6, δ = –12
|α + β + γ + δ| = 32