NCERT Class 9 Science MCQ | Chapter 4 Descrobing Motion Around Us
1. The motion of an object along a straight line is called:
(A) Circular motion
(B) Linear motion
(C) Oscillatory motion
(D) Periodic motion
Answer: (B) Linear motion
2. Which of the following is an example of linear motion?
(A) A car moving along a straight highway
(B) A satellite moving around Earth
(C) A child on a merry-go-round
(D) A stone moving in a circle
Answer: (A) A car moving along a straight highway
3. To describe the position of an object, we need to specify a:
(A) Speedometer
(B) Reference point
(C) Stopwatch only
(D) Mass
Answer: (B) Reference point
4. The position of an object is described using its:
(A) Distance only
(B) Direction only
(C) Distance and direction with respect to a reference point
(D) Speed and acceleration
Answer: (C) Distance and direction with respect to a reference point
5. An object is said to be in motion when its position with respect to a reference point:
(A) Remains constant
(B) Changes with time
(C) Becomes zero
(D) Becomes negative
Answer: (B) Changes with time
6. An object is said to be at rest when its position with respect to a reference point:
(A) Changes with time
(B) Does not change with time
(C) Becomes negative
(D) Becomes infinite
Answer: (B) Does not change with time
7. In a straight-line motion, positions to the right of the reference point are generally taken as:
(A) Negative
(B) Positive
(C) Zero
(D) Undefined
Answer: (B) Positive
8. The total path length travelled by an object is called:
(A) Displacement
(B) Distance travelled
(C) Velocity
(D) Acceleration
Answer: (B) Distance travelled
9. Displacement is defined as the:
(A) Total path length travelled
(B) Net change in position between two given instants
(C) Product of speed and time
(D) Change in speed only
Answer: (B) Net change in position between two given instants
10. Which quantity requires both magnitude and direction for its complete description?
(A) Distance
(B) Speed
(C) Displacement
(D) Time
Answer: (C) Displacement
11. The SI unit of distance and displacement is:
(A) Second
(B) Metre
(C) Metre per second
(D) Metre per second squared
Answer: (B) Metre
12. An athlete travels 160 m along a straight track and finally has a displacement of 40 m. Which statement is correct?
(A) Distance is less than displacement
(B) Distance is equal to displacement
(C) Distance is greater than displacement
(D) Both are zero
Answer: (C) Distance is greater than displacement
13. The magnitude of displacement is the:
(A) Total path length travelled
(B) Distance between the object’s positions at two instants
(C) Time taken by the object
(D) Speed of the object
Answer: (B) Distance between the object’s positions at two instants
14. For motion in a straight line, distance travelled and magnitude of displacement are equal when the object:
(A) Changes direction repeatedly
(B) Moves in one direction without turning back
(C) Comes back to its starting point
(D) Moves in a circle
Answer: (B) Moves in one direction without turning back
15. If an object returns to its original position, its displacement is:
(A) Maximum
(B) Equal to distance travelled
(C) Zero
(D) Negative
Answer: (C) Zero
16. An instant of time is:
(A) A duration between two clock readings
(B) A single reading of a clock at a given point of time
(C) The total time travelled
(D) The average time
Answer: (B) A single reading of a clock at a given point of time
17. A time interval is:
(A) A single clock reading
(B) The time duration between two instants
(C) A position of an object
(D) A direction
Answer: (B) The time duration between two instants
18. Average speed is calculated by:
(A) Displacement ÷ time interval
(B) Total distance travelled ÷ time interval
(C) Change in velocity ÷ time interval
(D) Distance × time
Answer: (B) Total distance travelled ÷ time interval
19. Average speed provides information about:
(A) Speed and direction
(B) How fast or slow an object moves
(C) Direction only
(D) Acceleration only
Answer: (B) How fast or slow an object moves
20. The SI unit of average speed is:
(A) m
(B) s
(C) m/s
(D) m/s²
Answer: (C) m/s
21. An object moving equal distances in equal intervals of time is said to be in:
(A) Non-uniform motion
(B) Uniform motion
(C) Circular motion only
(D) Oscillatory motion
Answer: (B) Uniform motion
22. In uniform motion in a straight line, the object moves with:
(A) Constant speed
(B) Increasing speed only
(C) Decreasing speed only
(D) Zero speed
Answer: (A) Constant speed
23. If an object travels unequal distances in equal intervals of time, its motion is:
(A) Uniform
(B) Non-uniform
(C) Stationary
(D) Circular only
Answer: (B) Non-uniform
24. Average velocity is defined as:
(A) Total distance divided by time
(B) Displacement divided by time interval
(C) Speed multiplied by time
(D) Acceleration divided by time
Answer: (B) Displacement divided by time interval
25. Average velocity requires specification of:
(A) Magnitude only
(B) Direction only
(C) Magnitude and direction
(D) Time only
Answer: (C) Magnitude and direction
26. The SI unit of average velocity is:
(A) m
(B) m/s
(C) m/s²
(D) s
Answer: (B) m/s
27. Average acceleration is defined as:
(A) Change in velocity divided by time interval
(B) Change in distance divided by time
(C) Distance divided by velocity
(D) Velocity multiplied by time
Answer: (A) Change in velocity divided by time interval
28. The SI unit of average acceleration is:
(A) m/s
(B) m
(C) m/s²
(D) km/h
Answer: (C) m/s²
29. If the magnitude of velocity of an object is increasing, the average acceleration is in the:
(A) Direction opposite to velocity
(B) Direction of velocity
(C) Direction perpendicular to velocity
(D) Zero direction
Answer: (B) Direction of velocity
30. If the magnitude of velocity is decreasing, the average acceleration is:
(A) In the direction of velocity
(B) Opposite to the direction of velocity
(C) Always zero
(D) Perpendicular to velocity
Answer: (B) Opposite to the direction of velocity
31. A position-time graph represents:
(A) Change in position with time
(B) Change in mass with time
(C) Change in temperature with time
(D) Change in force with time
Answer: (A) Change in position with time
32. A straight-line position-time graph indicates:
(A) Constant velocity
(B) Increasing mass
(C) Zero distance
(D) Circular motion
Answer: (A) Constant velocity
33. A curved position-time graph indicates that the velocity is:
(A) Constant
(B) Not constant
(C) Always zero
(D) Undefined
Answer: (B) Not constant
34. The slope of a position-time graph gives information about:
(A) Mass
(B) Velocity
(C) Acceleration only
(D) Time
Answer: (B) Velocity
35. A horizontal straight line parallel to the time axis on a position-time graph represents:
(A) Uniformly accelerated motion
(B) An object at rest
(C) Increasing velocity
(D) Circular motion
Answer: (B) An object at rest
36. In the velocity-time graph, the slope of the graph gives:
(A) Distance
(B) Displacement
(C) Acceleration
(D) Position
Answer: (C) Acceleration
37. A velocity-time graph that is a straight horizontal line indicates:
(A) Constant velocity and zero acceleration
(B) Increasing velocity
(C) Decreasing velocity
(D) Increasing acceleration
Answer: (A) Constant velocity and zero acceleration
38. The area under a velocity-time graph represents:
(A) Acceleration
(B) Displacement
(C) Speed
(D) Time
Answer: (B) Displacement
39. A car moves with a constant velocity of 20 m/s for 6 s. Its displacement is:
(A) 26 m
(B) 120 m
(C) 3.3 m
(D) 100 m
Answer: (B) 120 m
40. Which equation represents the first kinematic equation?
(A) v = u + at
(B) s = ut + 1/2 at²
(C) v² = u² + 2as
(D) s = vt
Answer: (A) v = u + at
41. Which equation is the second kinematic equation?
(A) v = u + at
(B) s = ut + 1/2 at²
(C) v² = u² + 2as
(D) a = v/t
Answer: (B) s = ut + 1/2 at²
42. Which equation relates velocity, initial velocity, acceleration and displacement without time?
(A) v = u + at
(B) s = ut + 1/2 at²
(C) v² = u² + 2as
(D) s = vt
Answer: (C) v² = u² + 2as
43. The kinematic equations given in the chapter are valid when:
(A) Acceleration is constant
(B) Speed is always zero
(C) The object is at rest
(D) Motion is always circular
Answer: (A) Acceleration is constant
44. A car has an initial velocity of 10 m/s and acceleration of 2 m/s². What will be its velocity after 5 s?
(A) 10 m/s
(B) 12 m/s
(C) 20 m/s
(D) 25 m/s
Answer: (C) 20 m/s
45. A bus moving at 36 km/h increases its velocity to 54 km/h in 10 s. Its average acceleration is:
(A) 0.5 m/s²
(B) 1 m/s²
(C) 2 m/s²
(D) 5 m/s²
Answer: (A) 0.5 m/s²
46. When a moving bus comes to rest because of braking, its acceleration is:
(A) Always positive
(B) Opposite to the direction of velocity
(C) Always zero
(D) Perpendicular to velocity
Answer: (B) Opposite to the direction of velocity
47. When an object moves in a circular path, its motion is called:
(A) Linear motion
(B) Circular motion
(C) Oscillatory motion
(D) Random motion
Answer: (B) Circular motion
48. The distance travelled by an object in one complete revolution of a circular path of radius R is:
(A) R
(B) πR
(C) 2πR
(D) 2R
Answer: (C) 2πR
49. In uniform circular motion, the speed of the object is:
(A) Constant
(B) Always zero
(C) Continuously increasing
(D) Continuously decreasing
Answer: (A) Constant
50. An object undergoing uniform circular motion is accelerated because:
(A) Its speed continuously increases
(B) Its mass continuously changes
(C) Its direction of velocity continuously changes
(D) Its displacement is always zero
Answer: (C) Its direction of velocity continuously changes
NCERT Class 9 Science MCQ | Chapter 4 Descrobing Motion Around Us
Assertion–Reason Questions
Choose the correct option:
(A) Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
(B) Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
(C) Assertion is true, but Reason is false.
(D) Assertion is false, but Reason is true.
1. Assertion: The displacement of an object can be zero even when the object has travelled some distance.
Reason: Displacement is the net change in the position of an object between two given instants.
Answer: (A)
2. Assertion: Average speed does not provide information about the direction of motion.
Reason: Average speed is calculated using total distance travelled, which has no direction.
Answer: (A)
3. Assertion: An object moving with constant velocity has zero acceleration.
Reason: Acceleration depends on how quickly the velocity of an object changes.
Answer: (A)
4. Assertion: A straight-line position-time graph indicates that an object is moving with constant velocity.
Reason: The slope of a position-time graph gives information about the rate of change of position with time.
Answer: (A)
5. Assertion: An object undergoing uniform circular motion is accelerated even though its speed remains constant.
Reason: In uniform circular motion, the direction of velocity continuously changes.
Answer: (A)
