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. When a 40-N force, parallel to the incline and directed up the incline, is applied to a crate on
a frictionless incline that is 30◦ above the horizontal, the acceleration of the crate is 2.0 m/s,up the incline. The mass of the crate is:
A. 3.8 kg
B. 4.1 kg
C. 5.8 kg
D. 6.2 kg
E. 10 kg
2. The “reaction” force does not cancel the “action” force because:
A. the action force is greater than the reaction force
B. they are on different bodies
C. they are in the same direction
D. the reaction force exists only after the action force is removed
E. the reaction force is greater than the action force
3. A book rests on a table, exerting a downward force on the table. The reaction to this force is:
A. the force of Earth on the book
B. the force of the table on the book
C. the force of Earth on the table
D. the force of the book on Earth
E. the inertia of the book
4. A lead block is suspended from your hand by a string. The reaction to the force of gravity on
the block is the force exerted by:
A. the string on the block
B. the block on the string
C. the string on the hand
D. the hand on the string
E. the block on Earth
5. A 5-kg concrete block is lowered with a downward acceleration of 2.8 m/s by means of a rope.The force of the block on the rope is:
A. 14 N, up
B. 14 N, down
C. 35 N, up
D. 35 N, down
E. 49 N, up
6. A 90-kg man stands in an elevator that is moving up at a constant speed of 5.0 m/s. The force
exerted by him on the floor is about:
A. zero
B. 90 N
C. 880 N
D. 450 N
E. 49 N
7. A 90-kg man stands in an elevator that has a downward acceleration of 1.4 m/s. The force
exerted by him on the floor is about:
A. zero
B. 90 N
C. 760 N
D. 880 N
E. 1010 N
8. A 5-kg concrete block is lowered with a downward acceleration of 2.8 m/s by means of a rope.
The force of the block on Earth is:
A. 14 N, up
B. 14 N, down
C. 35 N, up
D. 35 N, down
E. 49 N, up
9. A 13-N weight and a 12-N weight are connected by a massless string over a massless, frictionless
pulley. The 13-N weight has a downward acceleration with magnitude equal to that of a freely
falling body times:
A. 1
B. 1/12
C. 1/13
D. 1/25
E. 13/25
10. A massless rope passes over a massless pulley suspended from the ceiling. A 4-kg block is
attached to one end and a 5-kg block is attached to the other end. The acceleration of the 5-kg
block is:
A. g/4
B. 5g/9
C. 4g/9
D. g/5
E. g/9
11. A short 10-g string is used to pull a 50-g toy across a frictionless horizontal surface. If a
3.0 × 10−2-N force is applied horizontally to the free end, the force of the string on the toy, at
the other end, is:
A. 0.15 N
B. 6.0 × 10−3 N
C. 2.5 × 10−2 N
D. 3.0 × 10−2 N
E. 3.5 × 10−2 N
12. A brick slides on a horizontal surface. Which of the following will increase the magnitude of
the frictional force on it?
A. Putting a second brick on top
B. Decreasing the surface area of contact
C. Increasing the surface area of contact
D. Decreasing the mass of the brick
E. None of the above
13. The coefficient of kinetic friction:
A. is in the direction of the frictional force
B. is in the direction of the normal force
C. is the ratio of force to area
D. can have units of newtons
E. is none of the above
14. When the brakes of an automobile are applied, the road exerts the greatest retarding force:
A. while the wheels are sliding
B. just before the wheels start to slide
C. when the automobile is going fastest
D. when the acceleration is least
E. at the instant when the speed begins to change
15. A forward horizontal force of 12 N is used to pull a 240-N crate at constant velocity across a
horizontal floor. The coefficient of friction is:
A. 0.5
B. 0.05
C. 2
D. 0.2
E. 20
16. The speed of a 4.0-N hockey puck, sliding across a level ice surface, decreases at the rate of
0.61 m/s. The coefficient of kinetic friction between the puck and ice is:
A. 0.062
B. 0.41
C. 0.62
D. 1.2
E. 9.8
17. A 40-N crate rests on a rough horizontal floor. A 12-N horizontal force is then applied to it. If
the coefficients of friction are μs = 0.5 and μk = 0.4, the magnitude of the frictional force on
the crate is:
A. 8 N
B. 12 N
C. 16 N
D. 20 N
E. 40 N
18. A 24-N horizontal force is applied to a 40-N block initially at rest on a rough horizontal surface.
If the coefficients of friction are μs = 0.5 and μk = 0.4, the magnitude of the frictional force on
the block is:
A. 8 N
B. 12 N
C. 16 N
D. 20 N
E. 400 N
19. A horizontal shove of at least 200 N is required to start moving a 800-N crate initially at rest
on a horizontal floor. The coefficient of static friction is:
A. 0.25
B. 0.125
C. 0.50
D. 4.00
E. none of these
20. A force Fn (larger than the largest possible force of static friction) is applied to the left to an
object moving to the right on a horizontal surface. Then:
A. the object must be moving at constant speed
B. Fn and the friction force act in opposite directions
C. the object must be slowing down
D. the object must be speeding up
E. the object must come to rest and remain at rest
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