# Important Physics MCQS For CSS PMS PPSC FPSC NTS SET 13 Read important Physics MCQS For Exam.These physics  General Knowledge Mcqs Contain  of World Geography, Atmosphere, Science & Literature, events Mcqs, Current Affairs Mcqs , Pakistan Affairs Mcqs and International Organizations. These general knowledge questions are very important for all type of exams conducted by Fpsc, Nts, Kppsc, Ppsc, Spsc, Bpsc, Ots, Uts, Pts, Cts, Ats, etea and other testing agencies of Pakistan.

##### Note: The bold option is the right answer for the given MCQ’S:

1. A man wishes to pull a crate 15 m across a rough floor by exerting a force of 100 N. The
coefficient of kinetic friction is 0.25. For the man to do the least work, the angle between the
force and the horizontal should be:
A. 0
B. 14◦
C. 43◦
D. 66◦
E. 76◦

2. A particle moves 5 m in the positive x direction while being acted upon by a constant force
Fn = (4 N)ˆi + (2 N)ˆj − (4 N)ˆk. The work done on the particle by this force is:

A. 20 J
B. 10 J
C. −20 J
D. 30 J
E. is impossible to calculate without knowing other forces

3. A block is attached to the end of an ideal spring and moved from coordinate xi to coordinate
xf . The relaxed position is at x = 0. The work done by spring is positive if:
A. xi = 2 cm and xf = 4 cm
B. xi = −2 cm and xf = 4 cm
C. xi = −2 cm and xf = −4 cm
D. xi = 2 cm and xf = −4 cm
E. xi = −4 cm and xf = −2 cm

4. When a certain rubber band is stretched a distance x, it exerts a restoring force of magnitude
F = Ax, where A is a constant. The work done by a person in stretching this rubber band
from x = 0 to x = L, beginning and ending at rest, is:
A. AL2
B. A + 2L
C. A + 2L2
D. A/L
E. AL2/2

5. When a certain rubber band is stretched a distance x, it exerts a restoring force of magnitude
F = ax+bx2, where a and b are constants. The work done in stretching this rubber band from
x = 0 to x = L is:
A. aL2 + bLx3
B. aL + 2bL2
C. a + 2bL
D. bL
E. aL2/2 + bL3/3 6. An ideal spring is hung vertically from the ceiling. When a 2.0-kg mass hangs at rest from it
the spring is extended 6.0 cm from its relaxed length. A downward external force is now applied
to the mass to extend the spring an additional 10 cm. While the spring is being extended by
the force, the work done by the spring is:
A. −3.6 J
B. −3.3 J
C. −3.4 × 10−5 J
D. 3.3 J
E. 3.6 J

7. An ideal spring is hung vertically from the ceiling. When a 2.0-kg block hangs at rest from it
the spring is extended 6.0 cm from its relaxed length. A upward external force is then applied
to the block to move it upward a distance of 16 cm. While the block is moving upward the
work done by the spring is:
A. −1.0 J
B. −0.52 J
C. −0.26 J
D. 0.52 J
E. 1.0 J

8. Which of the following bodies has the largest kinetic energy?
A. Mass 3M and speed V
B. Mass 3M and speed 2V
C. Mass 2M and speed 3V
D. Mass M and speed 4V
E. All four of the above have the same kinetic energy

9. Two trailers, X with mass 500 kg and Y with mass 2000 kg, are being pulled at the same speed.
The ratio of the kinetic energy of Y to that of X is:
A. 1:1
B. 2:1
C. 4:1
D. 9:1
E. 1500:1

10. A 8000-N car is traveling at 12 m/s along a horizontal road when the brakes are applied. The
car skids to a stop in 4.0 s. How much kinetic energy does the car lose in this time?
A. 4.8 × 104 J
B. 5.9 × 104 J
C. 1.2 × 105 J
D. 5.8 × 105 J
E. 4.8 × 106 J

11. The velocity of a particle moving along the x axis changes from vi to vf . For which values of
vi and vf is the total work done on the particle positive?
A. vi = 5m/s, vf =2m/s
B. vi = 5m/s, vf = −2 m/s
C. vi = −5 m/s, vf = −2 m/s
D. vi = −5 m/s, vf = 2m/s
E. vi = 2m/s, vf = −5 m/s

12. An object is constrained by a cord to move in a circular path of radius 0.5 m on a horizontal
frictionless surface. The cord will break if its tension exceeds 16 N. The maximum kinetic
energy the object can have is:
A. 4 J
B. 8 J
C. 16 J
D. 32 J
E. 64 J

13. The weight of an object on the moon is one-sixth of its weight on Earth. The ratio of the
kinetic energy of a body on Earth moving with speed V to that of the same body moving with
speed V on the moon is:
A. 6:1
B. 36:1
C. 1:1
D. 1:6
E. 1:36

14. Which of the following is the correct combination of dimensions for energy?
A. MLT
B. LT2/m
C. ML2/T2
D. M2L3T
E. ML/T2

15. The amount of work required to stop a moving object is equal to:
A. the velocity of the object
B. the kinetic energy of the object
C. the mass of the object times its acceleration
D. the mass of the object times its velocity
E. the square of the velocity of the object

16. A 5.0-kg cart is moving horizontally at 6.0 m/s. In order to change its speed to 10.0 m/s, the
net work done on the cart must be:
A. 40 J
B. 90 J
C. 160 J
D. 400 J
E. 550 J

17. An 8-N block slides down an incline. It has an initial speed of 7 m/s. The work done by the
resultant force on this block is:
A. 3 J
B. 6 J
C. 56 J
E. none of these

18. A 4-kg cart starts up an incline with a speed of 3 m/s and comes to rest 2 m up the incline.
The total work done on the car is:
A. 6 J
B. 8 J
C. 12 J
D. 18 J

19. Two objects with masses of m1 and m2 have the same kinetic energy and are both moving to
the right. The same constant force Fn is applied to the left to both masses. If m1 = 4m2, the
ratio of the stopping distance of m1 to that of m2 is:
A. 1:4
B. 4:1
C. 1:2
D. 2:1
E. 1:1

20. A Boston Red Sox baseball player catches a ball of mass m that is moving toward him with
speed v. While bringing the ball to rest, his hand moves back a distance d. Assuming constant
deceleration, the horizontal force exerted on the ball by his hand is:
A. mv/d
B. mvd
C. mv2/d
D. 2mv/d
E. mv2/(2d) 