comprehensive definitions and mcqs of 10th class physics

1. Physics Def. & MCQs 1 Dr. Sajid Ali Talpur
Chapter 4
Force and Motion
(Don’t make life fun! Just run, run and run
until you get your work done otherwise you
will have none in the day of judgment under
sun…!

2. Physics Def. & MCQs 2 Dr. Sajid Ali Talpur
 Definitions
1. Motion: - When an object changes its position
with respect to its surrounding it is said to be in
motion.
2. Newton’s First Law of Motion: - it states that
“A body continues its state of rest or
uniform motion unless an external force acts on
it”
3. Inertia: -It is the property of matter by virtue of
which it opposes any change in its state of rest
or that of motion.
4. Force: -It is the agency that causes or tries to
change the state of rest or that of the motion of
the body.
5. Newton’s second law of motion: - According
to it
“When an unbalanced force acts on a body it
produces acceleration in the body in the
direction of force which is directly proportional
to the force and indirectly proportional to mass
of the body”
6. Newton’s third law of motion: - It states that
“Every action has an equal and opposite
reaction”
7. Weight: - Weight of the body is the
gravitational pull of the earth on the body.

3. Physics Def. & MCQs 3 Dr. Sajid Ali Talpur
8. Tension: -When an object is suspended by a
string the force that acts along the string and is
equal in magnitude and opposite in direction to
the weight is called tension.
9. Thrust: -A forcefully pushing force.
10. Up thrust: - It is the force that pushes things up
in water.
11. Reaction: -The opposing force of action (which
is the application of force)
12. Friction: -The resistive or opposing force to the
motion of the object generated when the two
surfaces or in contact.
13. Static Friction: -The friction between the body
and the surface when the body is at rest
14. Kinetic or dynamic Friction: -When the body
is in motion relative to the surface then the force
of friction between the object and surface is of
dynamic type.
15. Sliding Friction: -When a body slides on a
surface the corresponding force of friction is
called sliding friction.
16. Rolling Friction: -When a body rolls on a
surface the corresponding force of friction is
called rolling friction.

4. Physics Def. & MCQs 4 Dr. Sajid Ali Talpur
17. Limiting Friction: -The maximum static
friction when the object is on the verge of
slipping is called limiting friction.
18. Fluid Friction: -When a solid object moves
through a fluid (viscous medium), it experience
an opposing force on it, called fluid friction.
19. Resistance: -the force that prevents the motion.
20. Frame of Reference: -A set of coordinate axes
in terms of which the position or movement may
be specified or with reference to which physical
phenomenon may be stated mathematically.
21. Momentum: - It is defined as the product of
mass and velocity of the body.
22. Law of conservation of momentum: -The total
momentum of an isolated system before and
after collision remains conserved.

5. Physics Def. & MCQs 5 Dr. Sajid Ali Talpur
 Multiple Choice Questions
1. Momentum =
a) mass × velocity b) mass × acceleration
c) force × velocity d) force × acceleration
2. Find the incorrect statement about force:
a) its S.I unit is Newton
b) it always produces motion
c) force and acceleration are directly
proportional to each other
d) F=ma
 Questions 3 - 10
 Select from the terms below
A) Newton’s first law of motion
B) Newton’s second law of motion
C) Newton’s third law of motion
D) N.O.T
3. Every action has an equal and opposite reaction
is the statement of:
4. Also known as law of inertia
5. Acceleration is directly proportional to force is
the statement of:
6. Walking and firing of bullets are the examples
of:
7. Acceleration is directly proportional to mass is
the statement of:

6. Physics Def. & MCQs 6 Dr. Sajid Ali Talpur
8. Motion of boat obeys:
9. The flight of birds shown by the upward and
downward motion of their wings is in
accordance with:
10. Falling of leaves from plants on jerking is in
accordance with:
11. Far walking it is not necessary:
a) friction b) gravity
c) smoothness d) N.O.T
12. The unit of momentum is:
a) N b) N.m
c) Nm-
d) Nm-2
13. The maximum force of friction which just stops
body from sliding or moving is called:
a) rolling friction b) static friction
c) kinetic friction d) limiting friction
14. When force acting on a body is doubled its
acceleration becomes:
a) ½ b) ¼
c) doubled d) quadrupled
15. Find the force acting on a body of mass 10kg
moving with the acceleration of 5m/s2
.
a) 5N b) 15N
c) 30N d) 50N

7. Physics Def. & MCQs 7 Dr. Sajid Ali Talpur
16. What is mass of a body of weight 9.8N
a) 1kg b) 1g
c) 9.8kg d) 9.8g
17. How much acceleration will be produced in a
body of 15kg if force of 30N acts on it?
a) 1m/s2
b) 2m/s2
c) 3 m/s2
d) 3 m/s2
18. What is the mass of a body if the force of 20N
produces acceleration of 5 m/s2
a) 3kg b) 4kg
c) 15kg d) 400g
19. What is the weight of a body of mass 10kg
a) 10N b) 19.6N
c) 49N d) 98N
20. A stone weighing 2N is placed over wooden
table. The friction between stone and the table
is:
a) 0.08N b) 0.8N
c) 8N d) N.O.T
21. A force of 54N acts on a stationary body for 2s
and the body acquires velocity of 18m/s. the
mass of body is:
a) 6kg b) 8kg
c) 18kg d) 32kg

8. Physics Def. & MCQs 8 Dr. Sajid Ali Talpur
22. A body weighing 19.6N is resting at a place.
What force is needed to produce acceleration of
2 m/s2
a) 2N b) 4N
c) 9.8N d) 39.2N
 Questions 23-35
 Select from the terms below
A) True B) False
23. Mass and weight both have same unit
24. The weight of a body is always constant
25. m1v1 + m2v2 = m1u1 + m2u2 represents law of
conservation of momentum
26. Weight is a scalar quantity
27. Friction is directly proportional to deceleration
28. Friction will not be produced if the two surfaces
in contact are totally smooth.
29. Rolling friction is lesser than sliding friction
30. It is always necessary to apply force to stop
moving object
31. The quality of matter of a body is called its mass
32. Action and reactions have equal magnitude but
different direction

9. Physics Def. & MCQs 9 Dr. Sajid Ali Talpur
33. When an unbalanced force acts on a body it
always produces acceleration
34. The friction during motion is called kinetic
motion
35. It is dangerous to jump from moving train
because of inertia.
Answer Key
1 A 2 B 3 C
4 A 5 B 6 C
7 D 8 C 9 C
10 A 11 C 12 B
13 D 14 C 15 D
16 A 17 B 18 B
19 D 20 B 21 A
22 B 23 B 24 B
25 B 26 B 27 A
28 A 29 A 30 A
31 B 32 A 33 A
34 A 35 A