Measurement of Length and Motion Part 2: MCQs (Q26–Q50)
Part 2 — Questions 26–50 (Motion: types, distance vs displacement, speed basics)
26. Motion means
A. Staying in the same place
B. Change in position of an object with time ← Correct answer: B
C. Growing taller only
D. Increasing temperature only
Explanations:
A/C/D) Incorrect.
B) Correct — motion is change of position relative to a reference point over time.
27. Which of the following is NOT an example of motion?
A. A car moving on road
B. A tree fixed to ground (ignoring wind) ← Correct answer: B
C. Earth orbiting the Sun
D. A fan rotating
Explanations:
A/C/D) Examples of motion.
B) Correct — tree is stationary relative to ground (unless wind moves it).
28. Distance is different from displacement because distance is
A. A vector only
B. A scalar quantity (total path length), while displacement is vector ← Correct answer: B
C. Measured only in seconds
D. Negative always
Explanations:
A/C/D) Incorrect.
B) Correct — distance (scalar) has magnitude only; displacement has magnitude & direction.
29. If a person walks 3 m east then 4 m north, the resultant displacement from starting point is
A. 7 m
B. 5 m (by Pythagoras) ← Correct answer: B
C. 1 m
D. 12 m
Explanations:
A) Sum of distances, not displacement.
B) Correct — resultant = √(3²+4²)=5 m; direction northeast.
C/D) Incorrect.
30. A car moves with uniform speed. This means its
A. Speed increases constantly
B. Speed remains constant (magnitude unchanged) ← Correct answer: B
C. Direction remains constant always but speed changes
D. Acceleration is very large always
Explanations:
A/C/D) Incorrect.
B) Correct — uniform speed means constant speed; direction may or may not change (uniform circular motion is constant speed with changing direction).
31. Average speed is defined as
A. Shortest time only
B. Total distance traveled divided by total time taken ← Correct answer: B
C. Distance times time
D. Difference between distance and displacement
Explanations:
A/C/D) Incorrect.
B) Correct — average speed formula.
32. If a cyclist covers 20 km in 2 hours, the average speed is
A. 5 km/h
B. 10 km/h
C. 10 km/h ← Correct answer: C
D. 40 km/h
Explanations:
A) 5 km/h would be 10 km in 2 h.
B/C) Both show same but correct is 10 km/h; C explicitly indicated.
D) Incorrect.
33. Which graph is used to study motion showing distance (or displacement) vs time?
A. Bar graph only
B. Distance-time graph (or displacement-time graph) ← Correct answer: B
C. Pie chart only
D. Histogram only
Explanations:
A/C/D) Not specific to motion description.
B) Correct — distance-time graphs show how motion changes with time.
34. On a distance-time graph a straight line sloping upwards indicates
A. The object is at rest
B. Object is moving with uniform speed ← Correct answer: B
C. Object moving with increasing speed only
D. Graphing error only
Explanations:
A) Flat horizontal line indicates rest.
B) Correct — straight sloped line means constant rate (uniform speed).
C) Curved line indicates changing speed.
D) Not necessarily.
35. An object moving in a circle at constant speed has
A. Zero acceleration always
B. Non-zero acceleration because direction changes (centripetal acceleration) ← Correct answer: B
C. Not moving
D. Negative mass
Explanations:
A) Incorrect — direction change implies acceleration.
B) Correct — acceleration due to change in velocity direction.
C/D) Absurd.
36. Speed is a scalar quantity while velocity is a vector because velocity includes
A. Colour
B. Direction as well as magnitude ← Correct answer: B
C. Temperature only
D. Mass only
Explanations:
A/C/D) Incorrect.
B) Correct — velocity = speed + direction.
37. If a car’s velocity changes from 10 m/s to 20 m/s in 5 s, the average acceleration is
A. 1 m/s²
B. 2 m/s² ← Correct answer: B
C. 10 m/s²
D. 100 m/s²
Explanations:
A) (20-10)/10 =1 would be wrong time.
B) Correct — acceleration = (20−10)/5 = 2 m/s².
C/D) Too large.
38. Motion observed relative to another moving object is called
A. Absolute motion only
B. Relative motion ← Correct answer: B
C. Stationary observation only
D. Infinite motion
Explanations:
A/C/D) Incorrect.
B) Correct — motion depends on chosen reference frame.
39. Which of the following is true for displacement?
A. It is always equal to distance
B. It may be zero even when distance travelled is non-zero (e.g., round trip) ← Correct answer: B
C. It is always greater than distance
D. It is measured in litres
Explanations:
A/C/D) Incorrect.
B) Correct — e.g., start and end at same point => displacement zero.
40. An object moves 10 m east then 10 m west. Its distance and displacement respectively are
A. 0 m, 20 m
B. 20 m, 0 m ← Correct answer: B
C. 10 m, 10 m
D. 5 m, 5 m
Explanations:
A/C/D) Wrong order/values.
B) Correct — total distance = 10+10 =20 m; net displacement = 0.
41. Uniform motion means equal distances are covered in
A. Equal intervals of time → Correct ← Correct answer: A
B. Equal temperature changes
C. Equal directions only
D. Random time intervals
Explanations:
A) Correct — definition of uniform motion.
B/C/D) Incorrect.
42. The slope of a distance-time graph represents
A. Acceleration only
B. Speed (rate of change of distance with time) ← Correct answer: B
C. Temperature change
D. Mass flow
Explanations:
A) Slope of velocity-time graph gives acceleration.
B) Correct — slope (Δdistance/Δtime) = speed.
C/D) Not related.
43. Instantaneous speed refers to
A. Speed measured over long hours only
B. Speed of object at a particular instant (read from very small time interval) ← Correct answer: B
C. Speed unrelated to time
D. Speed measured in litres
Explanations:
A/C/D) Incorrect.
B) Correct — instantaneous speed is the speed at one instant.
44. Which unit is commonly used to express speed of cars?
A. Metre per second (m/s) sometimes
B. Kilometre per hour (km/h) ← Correct answer: B
C. Litres per km
D. Gram per second
Explanations:
A) Also used in physics but everyday use is km/h.
B) Correct — cars speeds typically given in km/h.
C/D) Irrelevant.
45. A bus travels at 60 km/h. How long will it take to cover 180 km?
A. 1 hour
B. 3 hours ← Correct answer: B
C. 180 hours
D. 0.33 hours
Explanations:
A) Incorrect.
B) Correct — time = distance/speed = 180/60 = 3 h.
C/D) Incorrect.
46. If distance-time graph is a horizontal straight line, the object is
A. Moving with increasing speed
B. At rest (distance constant) ← Correct answer: B
C. Moving backward only
D. Changing mass
Explanations:
A/C/D) Incorrect.
B) Correct — horizontal line indicates zero change in distance with time.
47. A man runs around a circular track of radius R once. His distance and displacement are respectively
A. 2πR, 0 → Correct ← Correct answer: A
B. 0, 2πR
C. 4πR, 2R
D. πR, πR
Explanations:
A) Correct — distance = circumference 2πR; displacement = zero (start and end same).
B/C/D) Incorrect.
48. When velocity changes direction but not magnitude, acceleration is
A. Zero always
B. Non-zero (centripetal) ← Correct answer: B
C. Equal to velocity always
D. Infinite
Explanations:
A/C/D) Incorrect.
B) Correct — acceleration due to change in direction even if speed constant.
49. If a car moves with constant speed in a straight line, what is its acceleration?
A. Positive and increasing
B. Zero (no change in velocity) ← Correct answer: B
C. Negative infinite
D. Variable randomly
Explanations:
A/C/D) Incorrect.
B) Correct — constant velocity (magnitude & direction) => zero acceleration.
50. Which of the following quantities is a vector?
A. Distance
B. Speed
C. Displacement ← Correct answer: C
D. Temperature
Explanations:
A/B/D) Scalars.
C) Correct — displacement has magnitude and direction.