| 1 |
A man pushes a wall and fails to displace it. He does: |
Negative work
Positive but not maximum work
No work at all
Maximum work
|
| 2 |
A body is dropped from a height of 20 m and rebounds to a height of 10 m. the loss of energy is: |
10%
45%
50%
75%
|
| 3 |
The gravity does no work, when the body moves: |
Horizontally
Vertically upwards
Vertically downward
At an angle of 45o with horizontal
|
| 4 |
A person weighing 20 mg walks on a level platform with a speed of 2 ms-1
. The work by the person against the
force of gravity is: |
Zero
2J
60J
600J
|
| 5 |
Ratio of dimension of K.E and power is: |
1:1
T:1
1:T
M:J
|
| 6 |
A body of mass 3 Kg lies on the surface on the table 2m high. It is moved on the surface by 4m. The change of
P.E will be: |
Zero
9.8 J
19.6 J
329 J
|
| 7 |
Which of the following types of force can do no work on the particle on which it acts? |
Frictional force
Gravitational force
Elastic force
Centripetal force
|
| 8 |
The momentum of a particle is numerically equal to its K.E. What is the velocity of a particle? |
9 ms<sup>-1</sup>
3 ms<sup>-1</sup>
2 ms-1
1 ms<sup>-1</sup>
|
| 9 |
When the velocity of a body is doubled: |
Its K.E is doubled
Its P.E is doubled
Its momentum is doubled
Its acceleration is doubled
|
| 10 |
If velocity time graph is a straight line parallel to time axis then body is |
Moving with zero acceleration
Moving with constant velocity
Covering equal displacement in equal intervals of time
All of these
|
| 11 |
At the highest point on the trajectory of a projectile, its |
Potential energy is minimum
Kinetic energy is maximum
Total energy is maximum
Kinetic energy is minimum
|
| 12 |
Two bodies are projected at angles and (90°–) with the horizontal at the same speed.The ratio of their
maximum heights is |
1 : 1
1 : tan
1 : tan
tan<sup>2</sup> : 1
|
| 13 |
Speedometer of an automobile measures |
Average velocity
Instantaneous velocity
Acceleration
Instantaneous speed
|
| 14 |
If a body changes its momentum from 100 N s to 200 N s in 10 s then the unbalanceexternal
force responsible to change the momentum is |
5 N
2.5 N
2n
10n
|
| 15 |
Swimming is possible on account of |
1<sup>st</sup> law of motion
2<sup>nd</sup> law of motion
3<sup>rd</sup> law of motion
Newton’s law of Gravitation
|
| 16 |
The angle of projection, at which the range of projectile would become half of its
maximum value. |
45Degree
30Degree
15Degree
60 Degree
|
| 17 |
. Time rate of change of momentum is equal to |
Force
Impulse
Velocity
Both A and C
|
| 18 |
select Which one of the following is not performing projectile motion |
A gas filled balloon
) Bullet fired from gun
A football kicked
A baseball shot
|
| 19 |
A rider uses Motorcycle safety helmet that extends the time of collision during accident hence
decreasing the |
Change of collisio
Force acting
Velocity
Impulse
|
| 20 |
A boy is travelling from Lahore to Karachi with uniform velocity . Its |
Speed changes
Acceleration changes
Direction of motion changes
Displacement from origin changes
|
| 21 |
A man has weight 980 N in a stationary lift. What will be his weight if the lift starts
moving up with anacceleration of 4.9 ms-2 |
980 N
1470 N
1980 N
1460 N
|
| 22 |
A monkey is accelerating down a string whose breaking strength is two third of his
weight. The minimumacceleration of the monkey should be |
1/3g
g
2/3 g
0 m/s2
|
| 23 |
Two astronauts in a satellite must have |
Same masses
Same real weights
Same apparent weights
None of these
|
| 24 |
The angular momentum of a body changes from 30 J-S to 50 J-S in 0.5 sec. The torque acting
on it is |
40 N-m
100 N-m
50 N-m
150 N-m
|
| 25 |
As in linear motion force determines linear acceleration where as in circular motion torque
determines its |
Angular acceleration
Linear acceleration
Vibratory acceleration
Tangential acceleration
|
| 26 |
A body is in translational equilibrium if |
P = 0
L = 0
F = 0
= 0
|
| 27 |
The centre of gravity of a triangular plate is at |
On end of the plate
The midpoint of any side of the plate
The midpoint of any side of the plate
The midpoint of any side of the plate
|
| 28 |
Two railway trucks of masses m and 3m move towards each other in opposite directions with speeds 2v and
v respectively. These trucks collide and stick together.
What is the speed of the trucks after the collision? |
<i>v/4</i>
<i>v/2</i>
<i>v</i>
<i>5v/4</i>
|
| 29 |
The rate of change of momentum of a body falling freely under gravity is equal to its |
Impulse
Kinetic energy
Pover
Weight
|
| 30 |
Two 8 N forces act on each end of the beam of length 0.60m. Two forces are parallel and acting opposite to
each other, the angle between the force and beam is 60o
, what is the torque of the couple exerted on the
beam: |
2.4 Nm
4.2 Nm
4.8 Nm
9.6 Nm
|
| 31 |
A rigid uniform bar of length 2.4 m is pivoted horizontally at its mid-point, weights are hung from two points
of the bar as shown in diagram. To maintain horizontal equilibrium, a couple is applied to the bar:
What is the torque and the direction of couple? |
40 N m clockwise
40 N m anti-clockwise
80 N m clockwise
80 N m anti-clockwise
|
| 32 |
What is the resultant force in the diagram shown? |
Zero
6N to left
6N to right
11N to right
|
| 33 |
In a one-dimensional elastic collision, the relative velocity of approach before collision is equal to: |
Sum of the velocities of the bodies
e times the relative velocity of separation after collision
1⁄𝑒 times the relative velocity of separation after collision
relative velocity of separation after collision
|
| 34 |
A body of mass m having an initial velocity v, makes head on elastic collision with a stationary body of mass
m. After the collision, the body of mass m comes to rest and only the body having mass M moves. This will
happen only when: |
m>>M
m<<M
) m=M
m=1M
|
| 35 |
The time of flight of a projectile is maximum when angle of projection is: |
30 Degree
45Degree
60Degree
90Degree
|
| 36 |
A stone is thrown upwards it returns to ground describing a parabolic path which of the following remains
constant: |
Speed of the ball
Kinetic energy of the ball
Vertical component of velocity
) Horizontal component of velocity
|
| 37 |
Two bodies are projected at angle 𝜽 𝒂𝒏𝒅 (𝟗𝟎 − 𝜽) to the horizontal with the same speed. The ratio of their
times of flight is: |
sin 𝜃 : 1
cos 𝜃 : 1
sin 𝜃 : cos𝜃
cos 𝜃 : sin𝜃
|
| 38 |
Newton’s third law concerns the forces of interaction between two bodies. Which of the following statement
relating to the third law is not correct: |
The two forces must be the same type
The two forces must act on different bodies
The two forces are always opposite in direction
The two forces are equal and opposite so the bodies are in equilibrium
|
| 39 |
Vertical component of velocity of the projectile at any instant ‘t’ from the ground is given by: |
𝑣𝑖𝑐𝑜𝑠𝜃
𝑣𝑖𝑐𝑜𝑠𝜃 − 𝑔<i>t</i>
𝑣𝑖𝑠𝑖𝑛𝜃 − 𝑔<i>t</i>
𝑣𝑖𝑠𝑖𝑛𝜃 + 𝑔<i>t</i>
|
| 40 |
If the range of a projectile is R, the potential energy will be maximum after the projectile has covered (from
start) distance equal to: |
<i>R/2</i>
<i>R/4</i>
<i>R</i>
<i>R/9</i>
|