🚀 Motion – Class 9 Science MCQs

Section 2: Speed, Velocity & Uniform/Non-uniform Motion (Q26–Q50)

Q26. Speed of an object is defined as:

A. Distance travelled per unit time
B. Displacement per unit time
C. Acceleration per unit time
D. Velocity per unit time

✅ Correct Answer: A. Distance travelled per unit time

Explanation:

• A. Correct, speed = distance ÷ time.
• B. That’s velocity.
• C. Wrong.
• D. Wrong.

Q27. SI unit of speed and velocity is:

A. km/h
B. m/s
C. cm/s
D. mph

✅ Correct Answer: B. m/s

Explanation:

• A. km/h is commonly used but not SI.
• B. Correct, SI = metres per second.
• C. cm/s not SI.
• D. mph not SI.

Q28. A car travels 120 km in 2 hours. Its average speed is:

A. 40 km/h
B. 60 km/h
C. 80 km/h
D. 100 km/h

✅ Correct Answer: B. 60 km/h

Explanation:

• Speed = distance ÷ time = 120 ÷ 2 = 60 km/h.
• Other options are miscalculations.

Q29. If the velocity of an object remains constant with time, its acceleration is:

A. Zero
B. Positive
C. Negative
D. Infinite

✅ Correct Answer: A. Zero

Explanation:

• A. Correct, no change in velocity → acceleration = 0.
• B & C. Only if velocity changes.
• D. Not possible.

Q30. The ratio of displacement to time is called:

A. Speed
B. Average speed
C. Velocity
D. Acceleration

✅ Correct Answer: C. Velocity

Explanation:

• A. Distance/time.
• B. Not displacement.
• C. Correct, displacement ÷ time = velocity.
• D. Wrong.

Q31. Velocity is zero when:

A. Distance is zero
B. Displacement is zero
C. Time is zero
D. Both B and C

✅ Correct Answer: B. Displacement is zero

Explanation:

• A. Distance may be non-zero but velocity depends on displacement.
• B. Correct, zero displacement → zero velocity.
• C. At time zero, velocity may exist.
• D. Only B is correct.

Q32. A body moving with uniform velocity will have:

A. Uniform acceleration
B. Non-uniform acceleration
C. Zero acceleration
D. Increasing acceleration

✅ Correct Answer: C. Zero acceleration

Explanation:

• A, B, D → Wrong, velocity doesn’t change.
• C. Correct, uniform velocity = no acceleration.

Q33. Which of the following has both magnitude and direction?

A. Speed
B. Velocity
C. Distance
D. Time

✅ Correct Answer: B. Velocity

Explanation:

• A. Speed = scalar.
• B. Correct, velocity = vector.
• C. Scalar.
• D. Scalar.

Q34. A bus moves 40 km north and then 30 km south. Net displacement is:

A. 70 km
B. 10 km
C. 40 km
D. 30 km

✅ Correct Answer: B. 10 km

Explanation:

• Displacement = final – initial position = 40 – 30 = 10 km north.
• Other options are incorrect.

Q35. If a car moves with constant speed in a circular path, its velocity:

A. Remains constant
B. Becomes zero
C. Changes continuously
D. Becomes negative

✅ Correct Answer: C. Changes continuously

Explanation:

• A. Wrong, direction changes.
• B. Not zero.
• C. Correct, velocity changes because direction changes.
• D. Not negative necessarily.

Q36. A particle moves in a straight line 5 m forward and 3 m back. Total distance = ?

A. 2 m
B. 8 m
C. 5 m
D. 3 m

✅ Correct Answer: B. 8 m

Explanation:

• Distance = total path = 5 + 3 = 8 m.
• Displacement = 2 m forward.

Q37. Average velocity is given by:

A. (Total distance) ÷ (Total time)
B. (Total displacement) ÷ (Total time)
C. (Final velocity – Initial velocity) ÷ time
D. Speed ÷ time

✅ Correct Answer: B. (Total displacement) ÷ (Total time)

Explanation:

• A. That’s average speed.
• B. Correct, displacement ÷ time = average velocity.
• C. Formula of acceleration.
• D. Wrong.

Q38. A runner goes 400 m around a circular track and returns to start. Displacement = ?

A. 400 m
B. 200 m
C. Zero
D. Cannot be found

✅ Correct Answer: C. Zero

Explanation:

• Distance = 400 m, but displacement = 0 (same start & end).

Q39. Instantaneous speed is measured by:

A. Stopwatch
B. Speedometer
C. Odometer
D. Barometer

✅ Correct Answer: B. Speedometer

Explanation:

• A. Stopwatch = time.
• B. Correct, speedometer shows speed at that instant.
• C. Odometer = distance covered.
• D. Barometer = pressure.

Q40. A particle is said to have uniform motion when:

A. It covers equal distances in equal time intervals
B. Velocity changes with time
C. Acceleration is not zero
D. Motion is oscillatory

✅ Correct Answer: A. It covers equal distances in equal time intervals

Explanation:

• A. Correct definition of uniform motion.
• B, C, D. Wrong.

Q41. Which is an example of uniform motion?

A. Car moving with variable speed
B. Earth revolving around the Sun
C. Train moving with constant speed on straight track
D. Stone falling freely

✅ Correct Answer: C. Train moving with constant speed on straight track

Explanation:

• A. Variable → non-uniform.
• B. Direction changes → non-uniform velocity.
• C. Correct.
• D. Acceleration present → non-uniform.

Q42. A body moving with non-uniform velocity has:

A. Constant displacement
B. Constant speed
C. Changing velocity
D. Constant acceleration

✅ Correct Answer: C. Changing velocity

Explanation:

• A, B, D. Wrong.
• C. Correct definition.

Q43. Which statement is correct?

A. Speed can be negative
B. Velocity can be negative
C. Distance can be negative
D. Time can be negative

✅ Correct Answer: B. Velocity can be negative

Explanation:

• A. Speed ≥ 0.
• B. Correct, velocity depends on direction.
• C. Distance ≥ 0.
• D. Time always positive.

Q44. Uniform speed means:

A. Constant displacement per unit time
B. Constant distance per unit time
C. Constant acceleration
D. No motion

✅ Correct Answer: B. Constant distance per unit time

Explanation:

• A. That’s velocity.
• B. Correct, equal distances in equal times.
• C. Acceleration = 0 here.
• D. Wrong.

Q45. If average velocity is zero, the displacement is:

A. Zero
B. Positive
C. Negative
D. Cannot say

✅ Correct Answer: A. Zero

Explanation:

• A. Correct, displacement ÷ time = 0 → displacement = 0.
• B, C. Wrong.
• D. Not true.

Q46. Which of the following is not correct?

A. Distance can never be zero
B. Displacement can be zero
C. Speed is scalar
D. Velocity is vector

✅ Correct Answer: A. Distance can never be zero

Explanation:

• A. Wrong, if body doesn’t move, distance = 0.
• B, C, D. Correct statements.

Q47. A car moves 60 km east and 80 km west. Net displacement = ?

A. 20 km east
B. 20 km west
C. 140 km
D. Zero

✅ Correct Answer: B. 20 km west

Explanation:

• Displacement = 80 – 60 = 20 km towards west.

Q48. Which motion has constant speed but variable velocity?

A. Circular motion
B. Rectilinear motion
C. Oscillatory motion
D. Projectile motion

✅ Correct Answer: A. Circular motion

Explanation:

• A. Correct, speed same but direction changes.
• B. Constant velocity possible.
• C, D. Not constant speed.

Q49. Average speed is equal to average velocity when:

A. Object moves in straight line with constant speed
B. Object moves in circular path
C. Object returns to start point
D. Motion is oscillatory

✅ Correct Answer: A. Object moves in straight line with constant speed

Explanation:

• A. Correct, then distance = displacement.
• B. Distance > displacement.
• C. Average velocity = 0, not equal to average speed.
• D. Wrong.

Q50. The slope of a distance-time graph gives:

A. Velocity
B. Acceleration
C. Speed
D. Both A and C

✅ Correct Answer: D. Both A and C

Explanation:

• A. Correct, slope = velocity.
• B. Wrong.
• C. Speed if direction not considered.
• D. Correct (velocity/speed depending on case).

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