1 Which of the following is a scalar quantity?
(a) Displacement
(b) Velocity
(c) Speed
(d) Acceleration
Answer: (c) Speed
Explanation: Speed is a scalar quantity because it has magnitude only, whereas displacement, velocity, and acceleration are vector quantities with both magnitude and direction.
2. The area under a velocity-time graph represents:
(a) Acceleration
(b) Displacement
(c) Speed
(d) Time
Answer: (b) Displacement
Explanation: The area under a velocity-time graph gives the displacement of the object over a period.
3. If an object moves in a straight line with constant speed, its acceleration is:
(a) Positive
(b) Negative
(c) Zero
(d) Variable
Answer: (c) Zero
Explanation: Acceleration is the rate of change of velocity. If speed is constant, there is no change in velocity, so acceleration is zero.
4. Which of the following is an example of uniformly accelerated motion?
(a) A car moving on a straight road at a constant speed
(b) A stone thrown upwards
(c) A ball rolling down an inclined plane without friction
(d) Both b) and c)
Answer: (d) Both (b) and (c)
Explanation: In both cases, the objects experience a constant acceleration due to gravity.
5. If a car accelerates uniformly from rest to a speed of 20 m/s in 10 seconds, its acceleration is
(a) 2 m/s²
(b) 4 m/s²
(c) 10 m/s²
(d) 20 m/s²
Answer: a) 2 m/s²
Explanation: Acceleration = (Final velocity – Initial velocity) / Time = (20 – 0) / 10 = 2 m/s².
6. The slope of a displacement-time graph gives
(a) Speed
(b) Acceleration
(c) Velocity
(d) Displacement
Answer: (c) Velocity
Explanation: The slope of a displacement-time graph represents the rate of change of displacement with time, which is velocity.
7. A car travels 100 km north and then 100 km south. What is its displacement?
(a) 0 km
(b) 100 km north
(c) 100 km south
(d) 200 km north
Answer: (a) 0 km
Explanation: Displacement is a vector quantity and depends on the initial and final positions. Since the car ends up where it started, the displacement is zero.
8. If the velocity of an object is constant, its acceleration is:
(a) Positive
(b) Negative
(c) Zero
(d) Infinite
Answer: (c) Zero
Explanation: Acceleration is the change in velocity. With constant velocity, there’s no change, hence acceleration is zero.
9. A body is moving with uniform velocity. Which of the following statements is true?
(a) The acceleration is zero.
(b) The speed is increasing.
(c) The distance traveled is decreasing.
(d) The velocity is changing.
Answer: (a) The acceleration is zero.
Explanation: Uniform velocity means no change in speed or direction, so acceleration is zero.
10 What does the area under an acceleration-time graph represent?
(a) Displacement
(b) Velocity
(c) Speed
(d) Force
Answer: (b) Velocity
Explanation: The area under an acceleration-time graph gives the change in velocity.
11. The SI unit of displacement is:
(a) Meter
(b) Second
(c) Kilometer
(d) Centimeter
Answer: (a) Meter
Explanation: Displacement is measured in meters, the standard SI unit for distance.
12. A car moving with a uniform velocity covers a distance of 150 meters in 5 seconds. What is its velocity?
(a) 15 m/s
(b) 20 m/s
(c) 25 m/s
(d) 30 m/s
Answer: (b) 30 m/s
Explanation: Velocity = Distance / Time = 150 m / 5 s = 30 m/s.
13. A body moving in a straight line at 5 m/s comes to rest in 10 seconds. The acceleration is:
(a) 0.5 m/s²
(b) -0.5 m/s²
(c) 1 m/s²
(d) -1 m/s²
Answer: b) -0.5 m/s²
Explanation: Acceleration = (Final velocity – Initial velocity) / Time = (0 – 5) / 10 = -0.5 m/s².
14. Which of the following quantities does not change in uniform circular motion?
(a) Velocity
(b) Acceleration
(c) Speed
(d) Displacement
Answer: (c) Speed
Explanation: In uniform circular motion, the speed remains constant, but the direction (and thus velocity) changes
15. A particle moving in a straight line covers equal distances in equal intervals of time. Its motion is
(a) Accelerated
(b) Uniform
(c) Retarded
(d) Non-uniform
Answer: (b) Uniform
Explanation: Covering equal distances in equal time intervals indicates uniform motion.
16. The acceleration of a body is constant. Which of the following graphs best represents its velocity-time relation?
(a) Straight line parallel to the time axis
(b) Straight line passing through the origin
(c) Parabolic curve
(d) Hyperbolic curve
Answer: (b) Straight line passing through the origin
Explanation: Constant acceleration results in a linear velocity-time graph.
17. The distance-time graph of an object moving with a uniform speed is:
(a) A straight line parallel to the time axis
(b) A straight line passing through the origin
(c) A curve
(d) A zigzag line
Answer: (b) A straight line passing through the origin
Explanation: Uniform speed results in a straight-line distance-time graph with a constant slope.
18. In which of the following cases is the object decelerating?
(a) A car moving at a constant speed
(b) A ball thrown upwards
(c) A ball dropped from a height
(d) A satellite orbiting the Earth
Answer: (b) A ball thrown upwards
Explanation: When a ball is thrown upwards, it slows down due to gravity, indicating deceleration.
19. The speed of an object at any instant is called:
(a) Average speed
(b) Instantaneous speed
(c) Uniform speed
(d) Relative speed
Answer: b) Instantaneous speed
Explanation: Instantaneous speed is the speed of an object at a particular moment in time.
20. A car moving at 30 m/s increases its speed to 50 m/s in 5 seconds. What is its acceleration?
(a) 2 m/s²
(b) 4 m/s²
(c) 6 m/s²
(d) 10 m/s²
Answer: (b) 4 m/s²
Explanation: Acceleration = (Final velocity – Initial velocity) / Time = (50 – 30) / 5 = 4 m/s².
21. The total path length traveled by an object in a given time interval is called:
(a) Displacement
(b) Distance
(c) Velocity
(d) Speed
Answer: (b) Distance
Explanation: Distance is a scalar quantity representing the total path length traveled, irrespective of direction.
22. A body moving with a uniform velocity in a straight line has:
(a) Uniform speed
(b) Constant acceleration
(c) Variable speed
(d) Decreasing velocity
Answer: a) Uniform speed
Explanation: Uniform velocity in a straight line implies both constant speed and no change in direction.
23. A particle travels 10 meters in 2 seconds, then 20 meters in the next 2 seconds. Its motion is:
(a) Uniform
(b) Accelerated
(c) Retarded
(d) Circular
Answer: (b) Accelerated
Explanation: Since the particle covers more distance in the same time interval, its velocity is increasing, indicating acceleration.
24. If the velocity-time graph of an object is a straight line parallel to the time axis, the object is:
(a) At rest
(b) Moving with uniform acceleration
(c) Moving with uniform velocity
(d) Moving with increasing acceleration
Answer: (c) Moving with uniform velocity
Explanation: A straight line parallel to the time axis on a velocity-time graph indicates constant velocity (zero acceleration).
25. The velocity of a particle at an instant is the slope of the:
(a) Distance-time graph
(b) Displacement-time graph
(c) Velocity-time graph
(d) Acceleration-time graph
Answer: (b) Displacement-time graph
Explanation: The slope of the displacement-time graph at any point gives the velocity of the particle at that instant.
26. Which of the following statements is true for a body under uniform acceleration?
(a) Velocity changes at a constant rate.
(b) Velocity remains constant.
(c) Displacement remains constant.
(d) Speed decreases.
Answer: (a) Velocity changes at a constant rate.
Explanation: Uniform acceleration means that the velocity of the body increases or decreases by the same amount every second.
27. A car travels 60 km at a speed of 30 km/h and then travels 60 km at 60 km/h. What is the average speed of the car?
(a) 40 km/h
(b) 45 km/h
(c) 48 km/h
(d) 50 km/h
Answer: (a) 40 km/h
Explanation: Average speed = Total distance / Total time. The total distance is 120 km, and the total time is 2 hours + 1 hour = 3 hours. Therefore, average speed = 120 km / 3 hours = 40 km/h.
28. The acceleration due to gravity on Earth is
(a) 8.8 m/s²
(b) 9.8 m/s²
(c) 10.8 m/s²
(d) 11.8 m/s²
Answer: (b) 9.8 m/s²
Explanation: The standard acceleration due to gravity on Earth is approximately 9.8 m/s².
29. If an object is thrown vertically upwards with an initial velocity, its velocity at the highest point is:
(a) Maximum
(b) Minimum
(c) Zero
(d) Equal to its initial velocity
Answer: (c) Zero
Explanation: At the highest point, the upward velocity of the object becomes zero before it starts descending.
30. A body moving in a straight line decelerates uniformly. Which of the following graphs best represents its velocity-time relation?
(a) A straight line with positive slope
(b) A straight line with negative slope
(c) A curve opening upwards
(d) A curve opening downwards
Answer: (b) A straight line with negative slope
Explanation: Uniform deceleration results in a linear velocity-time graph with a negative slope.
31. Which of the following quantities is not constant in uniform motion?
(a) Speed
(b) Velocity
(c) Acceleration
(d) Distance
Answer:(c) Acceleration
Explanation: In uniform motion, speed, velocity, and distance are constant, while acceleration is zero.
32. A car starts from rest and accelerates uniformly at 2 m/s². What is its velocity after 10 seconds?
(a) 10 m/s
(b) 15 m/s
(c) 20 m/s
(d) 25 m/s
Answer: c) 20 m/s
Explanation: Velocity = Initial velocity + Acceleration × Time = 0 + 2 × 10 = 20 m/s.
33. A ball is thrown vertically upward with a velocity of 20 m/s. How long will it take to reach the highest point? (Assume g = 10 m/s²)
(a) 1 second
(b) 2 seconds
(c) 3 seconds
(d) 4 seconds
Answer: (b) 2 seconds
Explanation: Time to reach the highest point = Initial velocity \ g = 20 / 10 = 2 seconds.
34. The equation v2 = u2 + 2as is used to calculate:
(a) Displacement
(b) Time
(c) Final velocity
(d) Acceleration
Answer: (c) Final velocity
Explanation: This equation relates the final velocity v, initial velocity u, acceleration a, and displacement s.
35. If a body travels with a constant velocity, its distance-time graph will be:
(a) A curve
(b) A straight line parallel to the time axis
(c) A straight line passing through the origin
(d) A zigzag line
Answer: (c) A straight line passing through the origin
Explanation: Constant velocity means the object covers equal distances in equal intervals of time, resulting in a straight-line graph.
36. The magnitude of the displacement of an object can never be
(a) Equal to the distance traveled
(b) Greater than the distance traveled
(c) Less than the distance traveled
(d) Zero
Answer: (b) Greater than the distance traveled
Explanation: Displacement is the shortest distance between the initial and final positions, so it can never be greater than the total distance traveled.
37. If a body is moving with a constant velocity, its acceleration is:
(a) Positive
(b) Negative
(c) Zero
(d) Infinite
Answer: (c) Zero
Explanation: Constant velocity means there is no change in speed or direction, so acceleration is zero.
38. The slope of a distance-time graph for a uniformly moving body represents:
(a) Velocity
(b) Acceleration
(c) Displacement
(d) Speed
Answer: (d) Speed
Explanation: The slope of a distance-time graph indicates the speed of the object, as it shows the rate at which distance changes over time.
39. Which of the following is a vector quantity?
(a) Distance
(b) Speed
(c) Time
(d) Displacement
Answer: (d) Displacement
Explanation: Displacement is a vector quantity because it has both magnitude and direction.
40. The area under a velocity-time graph represents