Solution
Solution
1001CJA101016250018 JA
PART-1 : PHYSICS
SECTION-I
1) A block of mass M has a circular cut with a frictionless surface as shown. The block rests on the
horizontal frictionless surface of a fixed table. Initially the right edge of the block is at x = 0, in a co-
ordinate system fixed to the table. A point mass m is released from rest at the topmost point of the
path as shown and it slides down. When the mass loses contact with the block, its position is x and
the velocity is v. At that instant, which of the following options is/are correct?
(A)
The x component of displacement of the center of mass of the block M is
(B)
The position of the point mass is
(C)
The velocity of the point mass m is
The velocity of the block M is
(D)
2) A small object moves counter clockwise along the circular path whose centre is at origin as shown
in figure. As it moves along the path, its acceleration vector continuously points towards point S.
3)
A particle of mass m is initially at rest at the origin. It is subjected to a force and starts moving along
the x-axis. Its kinetic energy K changes with time as where γ is a positive constant of
appropriate dimensions. Which of the following statements is (are) true?
(A) Ideally a rigid body has a perfectly definite and unchangign shape.
(B) Distances between different pairs of particle of rigid body do not change.
(C) Inter molecular forces for a rigid body are weak.
(D) No real body are truly rigid.
(A) the y-coordinate of the position of the projectile at time t is , where v is the
velocity of projection
the x-coordinate of the position of projectile at time t is , where v is the velocity of
(B)
projection
(C)
tan β = tan α – , where v is the velocity of projection
(D)
velocity of projection is
1) A 200 g, 20-cm diameter plastic disk is spun on an axle through its center by an electric motor.
What torque (in N-m) must the motor supply to take the disk from 0 to 1800 rpm in 4.0s ? (Take : π =
3.14)
(in Ns) provided by string during the time string turns through 90° is
3) We have a cube of side 4m as shown in the figure. The cube is massless but has masses at it's
vertices as shown. If the distance of centre of mass from the origin is r (in m) fill r2.
4) A block of mass 2.5 kg is placed over a fix rough incline (µ = 0.8) plane as shown. A time varying
force F = 5t N acting on block upward along the incline. Time (in sec) after which block will starts
5) Two particles A and B are simultaneously thrown from roof of two buildings as in figure. Their
speed are 2 m/s and 14 m/s and angles 45° and 45° as in figure. Vertical separation between the
buildings is 9m and horizontal separation is 22 m. The minimum gap in meter between the particles
when both are in air is d. Find the value of .
6) Spotlight S rotates in a horizontal plane with constant angular velocity of 0.1 rad/s. The spot of
light P moves along the wall at a distance of 3 m. The velocity of the spot P when θ = 45° (see Fig.)
is m/s.
SECTION-III
1) In the given figure both the blocks are in equilibrium. The acceleration of block 10 kg just after
cut the string is (in m/s2) (Assume both spring identical and massless. String is also massless)
2) In the given figure a force of magnitude 20t is applied on the lower block, where t is time in sec.
Coefficient of static friction between contact surfaces is 0.8. For what value of t upper block begin to
slip relative to lower block.
3) An impulse of I = 30N-sec is given at t = 0 to 3 kg block attached with 2 block with the help of
spring in natural length. Initially the system is at rest and all surfaces are smooth. Find velocity of
5) The world famous car Audi logo consist of four rings of each mass m and radius R as shown. Then
6) A boat starts from A with velocity (velocity of boat with respect to river) making an angle α =
30º with line AB and crosses the river. Velocity of river flow is as shown in figure. The line AC
makes an angle β = 60º with line AB. If the boat always remains on line AC then, the value of is
PART-2 : CHEMISTRY
SECTION-I
(A) CH2=C=C=CH2
(B)
(C) CH2=C=CH2
(D) CH2=CH–CH=O
4) From the following options which is/are correct for double chain silicates?
5) Given
2ZnS + 3O2 2ZnO + 2SO2
SO2 + ½O2 + H2O H2SO4
ZnO + H2SO4 ZnSO4 + H2O
2ZnSO4 + 2H2O 2Zn + 2H2SO4+O2
If 15 mole of ZnS reacts with excess of reactants then which of the following statement(s) is/are
correct?
6) 150 ml mixture of CO and CO2 mixed with 50 mL of O2 and sparked in eudiometer tube. The
residual gas after treatment with aq. KOH has a volume of 10 mL which remains unchanged when
treated with alkaline pyrogallol. If all the volumes are under the same conditions, point out correct
option(s) :
SECTION-II
(d) –OH (e) –OCH3 (f) (g) – (h) –CCl3 (i) –ONa
3) Total number of molecules in which all the possible bond angles are identical :
BF3, CF4, PF5, IF7, BeF2, SF4 , PF2Cl3 , CF2Cl2
5) The 'roasting' of 100.0 g of a copper ore yielded 72 g pure copper. If the ore is composed of Cu2S
and CuS with 4% inert impurity, calculate mole ratio of Cu2S and CuS in the original ore. The
reactions are : Cu2S + O2 2Cu + SO2 and CuS + O2 Cu + SO2
(Molar mass of Cu is 64 gm/mol)
6) Calculate the contraction in volume (in mL) of reaction mixture obtained by the combustion of 50
ml of a mixture containing 40% C2H4 and 60% CH4 (by volume) with excess of oxygen at room
temperature.
SECTION-III
1) Find total number of functional groups in the following organic compound [X].
3) Consider given data of lattice energy (in KJ/mol) of Halide of Na & Li.
In which option (1 to 8) lattice energy data most probably belong to NaI
4) Among the following, total number of species which contain total 4-degeneracy in second excited
state is
Li⊕ , H, He⊕ , Li2+, Be2+, Be3+
5) The reaction aA(g) → bB(g) + cC(g) is such that their is no volume change on conducting reaction.
Find the molar mass of mixture when some moles of A dissociated into B and C. The atomic weight
of A is 20 times molarity of solution when 100 ml, 3% (w/v) NaOH solution is mixed with 100 ml, 9%
(w/v) NaOH solution.
(Fill your answer as sum of digits till you get the single digit answer.)
6) An impure sample of NaHCO3 contains 12% of carbon. The percentage of impurity (by mass)
present in the sample is :
(Fill your answer as sum of digits till you get the single digit answer)
PART-3 : MATHEMATICS
SECTION-I
(A) t = 2
(B) t = –3
(C) t = –2
(D) t = 3
(A) x1 + x2 = 12
(B) y1 + y2 = 80
(C) x1 = 8, y1 = 16
(D) x2 = 4, y2 = 64
3) is divisible by :
(A)
(B)
(C)
(D)
6) In triangle ABC, vertex A is (1,1) and internal angle bisector x – y = 2 of angle B meets the
perpendicular bisector of side AC at (4,2). If equation of side AC is 2x + y = 3, then the correct
option(s) is/are :
(A)
Coordinate of vertex C is
(B) Image of vertex A in angle bisector x – y = 2 of angle B is (3, –1)
(C)
Slope of side BC is
(D)
Slope of side BC is
SECTION-II
2) If Dp = then
3) A circle of area 20 is centered at the point indicated by a solid dot in the accompanying figure.
Suppose that ΔABC is inscribed in that circle and has area 8. The central angles α, β and γ are as
5) Consider the pair of lines ax2 + 2hxy + by2 = 0. If slope of one of the line is three times that of
SECTION-III
1) The bisector of the acute angle between the lines 3x – 4y + 7 = 0 and 12x + 5y – 2 = 0 is ax + by
+ 9 = 0 then a + b is :
3) Consider a triangle ABC and let a, b and c denote the length of the sides opposite to vertices A,B
and C respectively. Suppose a = 3, b = 5 and the area of the triangle is . If ∠ACB is obtuse and
if r denotes the radius of the incircle of the triangle, then 4r2 is equal to :
4) If line 3ax + 2by = 12 belongs to family of lines x(1 + 2k) – ky – (2 + k) = 0, where k ∈ R, then
value of a + b is-
5) Distance of the origin from the line measured along the line
is
6) If , then value of is
ANSWER KEYS
PART-1 : PHYSICS
SECTION-I
Q. 1 2 3 4 5 6
A. A,C A,C A,B,D A,B,D A,B,C,D C,D
SECTION-II
Q. 7 8 9 10 11 12
A. 0.04 to 0.05 5.60 12.19 to 12.20 6.20 0.06 0.60
SECTION-III
Q. 13 14 15 16 17 18
A. 5 8 6 2 3 1
PART-2 : CHEMISTRY
SECTION-I
Q. 19 20 21 22 23 24
A. A,B,D A,B,D A,B,C,D A,B,C B,C,D A,B,D
SECTION-II
Q. 25 26 27 28 29 30
A. 14.00 10.00 3.00 3.00 1.00 100.00
SECTION-III
Q. 31 32 33 34 35 36
A. 6 4 2 0 3 7
PART-3 : MATHEMATICS
SECTION-I
Q. 37 38 39 40 41 42
A. A,B A,B,C,D A,B,C A,C,D B A,B,C
SECTION-II
Q. 43 44 45 46 47 48
A. 16.50 24.80 0.80 12.50 75.00 0.25
SECTION-III
Q. 49 50 51 52 53 54
A. 8 0 3 2 5 9
SOLUTIONS
PART-1 : PHYSICS
2) When angle between and is less than 90° it speeds up and greater them 90° it retards
3)
v = ct
Speed is proportional to time.
4)
5) y-coordinate is
⇒
⇒
⇒ [C is correct]
Rearrenging
⇒ [∴ D is correct]
6) atrolly= a0 = ...(1)
from figure we have
T cos 37° = 2g ...(2)
⇒ T = 25 N
T sin 37° = 2a ...(3)
⇒ a0 = 7.5 m/s2
from (i) we have
so, F = 75 N
7)
ωi = 0
ωf = 60π rad/s
τ = Iα
= 10–3 kg-m2
ωf = ωi + ∝
τ = 0.0471 N-m
8)
Impulse =
9)
10)
[5t = mgsinθ + µmgcosθ]
ℓ = 10
v = 0.6 m/s
13)
kx = 150
14)
2t – 8 = 8
t=8s
15)
I = ΔP
30 = 3(vf – 0) ⇒ vf = 10 m/s
⇒
Velocity of centre of mass remains constant because there is no external force on the system.
16) at t = s,
a = 2 ms–2
17)
PART-2 : CHEMISTRY
21)
22)
23)
CO + → CO2
Initial volume x 50
Final volume x–100 0 100 x = 110 ml
Total CO2 absorbed finally = 100 + 40 = 140 ml
25) x = a, i (2)
y = b, c, d, e, f, g, h (7)
26)
27) BF3, CF4 and BeF2 have all the possible B.A. identical.
28)
⇒X=3
29)
.......(2)
6x + 5y = 540
x = 60 gm
y = 36 gm
30)
33)
34)
∴ Molarity =
Molar mass of A = 1.5 × 20 = 30
If there is no volume change in the given reaction then a = b + c
Mmix =
36) Let the mass of the sample be 100 gm and mass of NaHCO3 be x gm.
wtC =
x = 12 × 7 = 84 gm
Weight of impurity = 16 gm
% Impurity = 16
PART-3 : MATHEMATICS
37) ⇒ t2 + t – 6 = 0
39)
t = –1, 3
(Rejected)
x = 8 only solution.
41)
On solving 3x + 5y = 0 and 15y + 105x = 32
We will get vertex A
(3x + 5y = 0) × 3
15y + 105x = 32
from equations
96x = 32 ⇒
Similarly
⇒
⇒ Equation of OD
⇒
again image of A in angle bisector x – y–2 = 0
lies on side BC
⇒
⇒ h = 3, k = –1 ⇒ (3,–1)
⇒ slope of side BC is
43)
1(–4k + 6) – k(–12 + 4) + 3(9 – 2k) = 0
–4k + 6 + 12k – 4k + 27 – 6k = 0
2k = 33
44)
C1 → C1 – C2
3m1 + m1 = ⇒ m1 =
3m1 . m1 = ⇒ 3
⇒ 3h2 = 4ab
48)
⇒ ⇒ t2 – 10t + 9 = 0
⇒ t = 1, 9 ⇒ tan2x = 0, 1
⇒ tanx = 0, ±1
∴ Product of solutions is =
∴ = 0.25
50) R1 → R1 – R2, R2 → R2 – R3
51)
–15 = 34 – c2
c2 = 49
c=7
⇒r=
r2 =
Now :
r=5
54) Δ = 3 Δcofactor = Δ2