Physics XI Karachi Board MCQs Chapter 3

Chapter 3 - Motion
1. The change of position of a body in a particular direction is called its __________.

(Displacement, Velocity, Acceleration)

2. The change of displacement with respect to the time is called __________.

(Speed, Velocity, Acceleration)

3. The rate of change of position in a particular direction is called __________.

Displacement, Velocity, Acceleration)

4. The total change in displacement divided by the total change in time of body is called its __________.

(Average Velocity, Instantaneuous Velocity, Uniform Velocity)

5. The change of displacement in a very small interval of time (time tends to zero) of a body is called its __________.

(Average Velocity, Instantaneous Velocity, Uniform Velocity)

6. When a body undergoes an acceleration then __________.

(Its speed increases, Its velocity increases, It falls toward the earth)

7. A force acts on a body that is free to move. We known that magnitude and direction of the force and the mass of the body. Newton’s second law of motion enables us to determine the body’s __________.

(Acceleration, Speed, Velocity)

8. A hole is drilled through the earth along the diameter and a stone dropped into it. When the stone is at the centre of the earth it has __________.

(Mass, Weight, Acceleration)

9. A force of 3N acts perpendicularly to a force of 4N. Their resultant has magnitude of __________.

(1N, 5N, 7N)

10. In __________ of the following examples the motion of the car not accelerated.

(Car turns a corner at constant speed of 29km/hr, Car climbs a steep hill with its speed dropping from 60 km/hr at the bottom to 15 km/hr at the top, Car climbs a steep hill at the constant speed of 40km/hr)

11. The algebraic sign of acceleration depends on __________.

(The choice of direction, Whether an object is speeding up or slowing down, The position of the object)

12. The acceleration due to gravity __________.

(has the same value every where in space, has the same value every where on the earth, varies with the latitude on the earth)

13. Swimming is possible because of __________ law of motion.

(First, Second, Third)

14. A vehicle is moving horizontally at 30m/s. It is then accelerated uniformly in the same direction at 0.5 m/s2 for 30 seconds. Its final speed is __________.

(180 m/s, 45.0 m/s, 90 m/s)

15. An object falls freely from rest with an acceleration of 10m/s2 (approximately). Then the distance traveled after 0.6 second is __________.

(1.8 m, 18.0 m, 3.6 m)

16. A trolley of mass 1.0kg travelling at 3m/s, collides with second trolley which is stationary. On collision the two trolley join together and continue to travel in the original direction with a common speed of 1.0 m/s. __________is the mass of second trolley.

(0.33kg, 0.67kg, 2.0kg)

17. A steel ball is dropped in a viscous fluid. It will __________.

(move down with uniform velocity, remain stationary, fall with uniform acceleration of 9.8 m/s2)

18. A trolley of mass 2kg moves with constant acceleration on a smooth horizontal surface. Its speed changes from 4m/s to 16 m/s during 6.0 seconds. The trolley has an acceleration of __________m/s2.

(0.5 , 0.66, 2)

19. During a stop a car comes to rest from a speed of 10 m/s in 5 seconds. Assuming a steady deceleration during this time, it will travel a distance of __________.

(2m, 10m, 25m)

20. A ball is dropped from a tall building falls to the ground. Ball reaches the ground in 3.0 seconds. __________ is the height of the building.

(15m, 30m, 45m)

21. A trolley of mass 2kg is moving at 15m/s. It collides head on with another trolley of mass 1kg initially at rest. The first trolley sticks with second one. __________ is the speed of both trolleys after collision.

(5m/s, 7.5m/s, 10m/s)

22. When a tennis ball is allowed to fall freely in air toward the ground. It is found that it acquires a uniform velocity. This is because the __________.

(Weight of the ball does not act beyond a certain speed, Upthrust of the displaced air supports the ball, Frictional force caused by the air increases with speed)

23. The force required to accelerate mass of 1kg at 1.0 m/s2 is __________.

(1N, 10N, 100N)

24. If a stone falls from rest with a uniform acceleration of 10m/s2 (approximately) then __________.

(It falls equal distance in successive seconds, it falls 10.0 m during the first second, its speed increases by 10 m/s each second)

25. The frictionless trolley is moving horizontally at 30m/s. It is then accelerated uniformly in the same direction at 0.5 m/s2 for 30.0 seconds. The final speed is __________.

(15 m/s, 45 m/s, 75 m/s)

26. A person covers half of its journey at a speed of 40 m/s and the other half at 50 m/s. His average speed during the whole journey is __________.

(45 m/s, 46 m/s, 48 m/s, 44.1 m/s)

27. An object is thrown vertically upward with a velocity of 40 m/s and returns after some time into the thrower’s hands with the same velocity. Average velocity during the whole movement is __________.

(40m/s, 60m/s, 80 m/s, 0)

28. A body starts from rest and moves with uniform acceleration of 10m/s2 in the first 10 seconds. During the next 10 seconds it moves with uniform velocity attained. The total distance covered by it is __________.

(200m, 1000m, 1500m, 500)

29. A ball A dropped from the top of a building while another ball B is thrown horizontally at the same time. The ball strikes the ground is __________.

(Ball A, Ball B, Both strikes simultaneously)

30. __________ of the following is one dimensional motion.

(The wheels of a moving train, the earth revolving round the sun, A train running on a straight track)

31. A body has an initial velocity of 8 m/s. After moving 4m its velocity is 12 m/s. The acceleration is __________m/s2.

(10, 100, 4)

32. A body starting from rest travels 120 m in 8th second. Assuring the motion to be uniform, its acceleration is __________m/s2.

(15, 16, 10)

33. A body thrown vertically up with a velocity of 10m/s, comes back in to the hand of the thrower after 4 seconds. Height attained by the body is __________. (Take g = 10m/s2)

(10m, 5m, 15m)

34. The total change in velocity of a body divided by the total time is called __________.

(Average acceleration, Instaneous Acceleration, Uniform Accelration)

35. The change in velocity of a body in a very small interval of time (time interval tends to zero) is called __________.

(Average acceleration, Instantaneous Acceleration, Uniform Acceleration)

36. When there is equal change in velocity in equal intervals of time, then acceleration is called __________.

(Average Acceleration, Instantaneous Acceleration, Uniform Acceleration)

37. Force is that agent which produces or tends to produce the __________.

(Speed in the body, Acceleration in the body, Constant velocity in the body)

38. Whenever a constant force is applied on a body then it will move with __________.

(Cosntant Speed, Constant Velocity, Constant Acceleration)

39. The direction of tension in string will always in the __________.

(Same direction of applied force, Opposite direction of applied force, None of the above)

40. A body of mass 10kg is suspended by a string, the tension produced in the string is __________. (Take g = 10m/s2)

(100N, 9.8 N, 980 N)

41. In elastic collision between the two bodies __________.

(Only mometum of the system is conserved, Only the kinetic Energy of the system is conserved, Both the kinetic Energy and Momentum of the system remain the same)

42. In inelastic collision between the two bodies __________.

(Only mometum of the system is conserved, Only the kinetic Energy of the system is conserved, Both the kinetic Energy and Momentum of the system remain the same)

43. If a lighter body collides elastically with a massive body at rest then the lighter bodies will __________.

(Rebound, Come to rest, Start to move with a velocity double of its initial)

44. The kinetic friction will always be __________.

(Greater than the static friction, Equal to the Static Friction, Less than the static Friction)

45. The unit of coefficient of friction in SI system is __________.

(Newton, Dyne, None of These (No Unit))

46. Due to the rise in temperature the coefficient of fluid friction will __________.

(Decrease, Increase, Remain the same)

47. A body of mass ‘m’ slides down a frictionless inclined plane making an angle q with the horizontal then __________ of the following statement is most appropriate.

(The component of its weight normal to the plane pulls it down the plane, The component of its weight parallel to the plane is balanced by the normal reaction of the plane, The body moves down the plane with a constant acceleration)

48. If a weight of 1 kg and 1gm are dropped from the same height simultaneously then __________.

(1kg will reach the ground earlier, 1gm weight will rach the ground earlier, bother will reach the ground at the same time)

49. If the velocity of the body is uniform then __________.

(Its speed remains uniform, Its speed and direction of motion will remain the same, Its acceleration is uniform)

50. If a particle is moving with constant speed in a circle then its velocity is __________.

(Zero, Uniform, Variable)