Chapter 13 MCQs with Answers
Chapter 3 with Answers
1. Which
graph best represents how the displacement of a vertically thrown ball varies
with time?
2. Which graph best shows how the velocity of a vertically thrown ball varies with time?
3.
A body whose instantaneous and
average velocities are equal is said to have
(a)
constant acceleration (b)
constant velocity
(c)
variable velocity (d)
variable acceleration
4.
Inertia of a body is a measure of
its
(a)
mass (b)
weight
(c)
velocity (d) momentum
5.
A body moving with velocity v has
energy E. Its momentum is
(a) E/v (b) Ev/2
(c) 2E/v (d) Ev
6.
An alternate unit to kg m/s
(a)
J s (b)
N s
(c)
N m (d)
N
7.
Change of linear momentum of a
body is called its (a)
acceleration (b) impulse
(c)
force (d)
energy
8.
A trolley of mass 3 kg moving with
a speed of 4 m/s collides with and remains attached to a stationary trolley of mass 1 kg. Their
combined momentum, in kg m/s,
after the collision is
(a)
4
(b)
7
(c)
8 (d)
12
9.
Forces in nature always occur
in
(a)
single form (b) pair form
(c)
triple form (d)
any form
10.
When two bodies move like a single
body after colliding each other, the collision is said to be
(a)
perfectly elastic (b)
partially elastic
(c)
perfectly inelastic (d) partially inelastic
11.
As a result of an elastic
collision between two masses m1 and m2 an exchange of
velocity takes place. For collision of this type
(a)
m1 >> m2 (b) m1
= m2
(c) m1 << m2
(c) one of the masses must be initially
at rest
12.
If a shell is fired from a canon
and explodes in air, then the total
(a)
momentum increases (b) momentum decreases
(c)
kinetic energy increases (d) kinetic
energy decreases
13.
A ball thrown up with a velocity
of 19.6 m/s returns back into the thrower’s hand after
(a)
1 s (b)
2 s
(c)
3 s (d)
4 s
14.
Lead balls each of mass m kg fall
on a horizontal plate at the rate of n balls per second. If they strike the
plate with a velocity of v m/s , the force exerted on the plate in N is
(a)
mvn (b)
mv/n
(c) mn/v (d) m/nv
15.
From the top of a building a ball
A is dropped while another ball B is thrown horizontally at the same instant.
Which ball will strike the ground first?
(a)
A
(b)
B
(c)
Both at the same time (d) Nothing
can be predicted
16.
In case of projectile motion, the
maximum height attained by a body is equal to its range. The angle of
projection with the horizontal is
(a) arc tan (1) (b) arctan (2)
(c) arctan (3) (d) arctan (4)
17.
The height H gained by a projectile is related to its
maximum range Rmax by
18.
The horizontal range of a
projectile is the same for the angles
(a)
600 and 800 (b)
400 and 700
(c) 450 and 550 (d)
400 and 500
19.
The time taken by a projectile to
reach maximum height is
20.
A ballistic trajectory is the path
followed by
(a)
an un-powered and unguided missile
(b)
a powered and guided missile
(c)
an un-powered but guided missile
(d)
a powered and guided missile
21.
A snooker ball moving with
velocity v collides head-on with another snooker ball of same mass at rest. If
the collision is elastic, the velocity of the second snooker ball is
(a)
zero (b)
uncertain
(c)
v (d)
2 v
22.
The time of flight of a projectile
is
23.
The velocity of a projectile at
the maximum height is
(a)
vi sinθ (b)
vi cosθ
(c)
maximum (d) zero
24.
With increasing angle of
projection, the vertical height gained by a projectile
(a)
decreases gradually
(b)
increases gradually
(c)
first increases and then
decreases (d) remains the same.
25.
The horizontal component of the
velocity of a projectile moving with initial velocity of 500 ms-1 at
an angle of 600 to the x-axis is
(a)
500 ms-1 (b)
1000 ms-1
(c)
250 ms-1 (d) zero
26.
A car is decelerating uniformly,
its velocity changing from 30 ms1
to 15 ms-1 in 75 m. How much further will it travel before coming to
rest?
(a)
25 m (b)
50 m
(c)
75 m (d)
100 m
27.
A body starts from rest at t = 0
and moves with constant acceleration. Which graph below best represents how the
displacement s of the body varies with time?
28.
Laws of motion are valid in those systems
which
(a)
are non-inertial (b)
are inertial
(c)
are at rest (d)
are in space
31.
Neutron (mass = 1 u) undergoes
elastic collision with stationary nitrogen nucleus (mass = 14 u). The velocity
of neutron after the collision is
(a)
0
(b)
less than the velocity of nitrogen
atom after collision
(c)
equal in magnitude to its initial
velocity but opposite direction
(d)
less in magnitude than its initial
velocity but with changed direction
32.
Area under the velocity – time
graph represents
(a)
speed (b) momentum
(c)
velocity (d) distance covered
33.
A body thrown up with a velocity
of 9.8 m/s reaches a maximum height of
(a)
9.8 m (b)
4.9 m
(c)
19.6 m (d)
44.1 m
34.
A force of 4 N acting on a body of mass 2 kg for 2 s
produces a rate of change of momentum of
(a)
1 kgms-1 (b)
2 kgms-1
(c)
4 kgms-1 (d) 8 kgms-1
35.
Dimensions of impulse are
(a)
[MLT] (b)
[MLT-1]
(c)
[MLT2] (d)
[MLT2]
36.
Collisions of gas molecules with
the walls of the container are the example of
(a)
inelastic collisions (b)
elastic collisions
(c)
partially elastic collisions (d)
partially inelastic collisions
37.
Gas molecules inside a container
constitute
(a)
an isolated system (b) a non-isolated system
(c) a
conservative system (d) a
non-conservative system
38.
A ball bouncing off a wall
(a)
obeys law of conservation of
energy
(b)
does not obey law of conservation
of energy (c) obeys law of conservation of momentum
(d)
does not obey law of conservation of momentum.
39.
Speed of a projectile is minimum
at the
(a)
point of landing (b)
point of projection
(c)
maximum height (d)
none of these
40.
What happens when a system of two
bodies undergoes an elastic collision?
(a)
The momentum of the system
changes
(b)
The momentum of the system does
not change
(c)
The bodies come to rest after
collision (d) The energy conservation law is violated.
Key to Test
Chapter 3
1
|
c
|
21
|
c
|
2
|
a
|
22
|
b
|
3
|
b
|
23
|
b
|
4
|
a
|
24
|
b
|
5
|
c
|
25
|
c
|
6
|
b
|
26
|
a
|
7
|
b
|
27
|
b
|
8
|
d
|
28
|
b
|
9
|
b
|
29
|
c
|
10
|
c
|
30
|
b
|
11
|
b
|
31
|
d
|
12
|
b
|
32
|
d
|
13
|
d
|
33
|
b
|
14
|
a
|
34
|
d
|
15
|
c
|
35
|
b
|
16
|
d
|
36
|
b
|
17
|
b
|
37
|
a
|
18
|
d
|
38
|
d
|
19
|
c
|
39
|
c
|
20
|
a
|
40
|
b
|
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