System of Particles and Rotational Motion Mock Test – Class 11 Physics

1. A rigid body rotates about a fixed axis under a constant net torque. Its rotational kinetic energy increases from to while it turns through . The net torque is

2. In ideal rolling without slipping down an incline, the work done by static friction on the rolling body is zero because

3. In the relation , the distance means

4. Use the graph description below.

The shaded area represents

5. A uniform square lamina is folded conceptually along one diagonal into two equal triangular halves. This observation supports that its centre of mass lies

6. A particle is fixed at the rim of a disc rotating with angular speed . If the radius of the disc is doubled while remains the same, the particle's centripetal acceleration becomes

7. In rolling without slipping, the condition is valid only when is measured in

8. A comparison between linear momentum and angular momentum is shown below. Which row is suitable?

9. A wheel rolls forward on a horizontal road without slipping. At the simplest classification level, its motion is a combination of

10. Assertion: The acceleration of the centre of mass of a system is decided by the net external force on the system.
Reason: Internal forces between particles of the system cancel in the total force balance.

11. The same force acts on the same body, but torque is calculated about two different points. The torque values may differ because

12. A particle moves in a circle about the origin under a force directed toward the origin. Its angular momentum about the origin is conserved because

13. Study the table and choose the row that correctly gives the total kinetic energy for rolling without slipping with centre-of-mass speed .

14. A thin ring rolls without slipping with centre-of-mass speed . If , its total kinetic energy is

15. Assertion: For two positive masses on a line, the centre of mass lies between the two particle positions.
Reason: is a weighted average of the two coordinates with positive weights.

16. A vector product is chosen instead of a scalar product when the required physical quantity must

17. For a continuous body, the centre-of-mass formula is obtained from the discrete-particle formula by replacing

18. The magnitude of is maximum when the angle between and is

19. A -versus- graph for a rotating body is a straight line from to . The work done by the torque is

20. A uniform metre scale is balanced at its mark. A weight is hung at the mark. To balance it, a weight should be hung at

21. For a rolling body descending an incline, the formula shows that the acceleration is independent of

22. A solid cylinder rolls without slipping down an incline. The frictional force on it acts up the incline. Its role is mainly to

23. Angular momentum of a particle about a point is defined as

24. Use the graph description below.

The slope of this graph is

25. A rolling solid cylinder is analysed using the instantaneous contact point as the axis. If , then is

26. A body rolls without slipping down an incline. If its shape factor is larger, then for the same vertical drop its translational speed at the bottom is smaller because

27. A claim says, "For several particles, can be found by averaging only the extreme left and extreme right coordinates." This method is reliable only when

28. For the same total mass and radius , a thin ring and a uniform disc rotate about their common central axis perpendicular to their planes. The ring has greater moment of inertia because

29. Work done by a constant torque during an angular displacement is

30. Moment of inertia is larger when more mass is placed farther from the axis mainly because

31. A vertical force acts downward at the right end of a horizontal rod pivoted at its left end. About the pivot, the torque tends to rotate the rod

32. A system of particles experiences zero net external torque about a fixed origin. Its total angular momentum about that origin

33. A graph of torque versus angular displacement is a straight horizontal line at from to . The work done by the torque is

34. A solid sphere rolls without slipping from rest down a vertical height . With , its speed at the bottom is

35. Study the table and identify the row that follows Newton's second law for a system.

36. Consider the following statements about angular momentum of a particle system.
I. Total angular momentum is a vector sum of individual angular momenta.
II. Net external torque changes total angular momentum of the system.
III. Internal torques always change total angular momentum even when they cancel in pairs.

37. Two unequal masses are placed at the ends of a light rod of length . If is at the left end and is at the right end with , the centre of mass lies

38. A uniform circular disc has moment of inertia about the central axis perpendicular to its plane. By symmetry, for two perpendicular diameters in its plane. The moment of inertia about a diameter is

39. A force acts at a point whose position vector from the origin is . The torque about the origin is

40. The value of is

41. The cross product equals

42. For a particle, and . A suitable analogy with linear motion is

43. A system of two blocks is pulled horizontally by an external force of . The blocks have masses and . Ignoring friction, the acceleration of the centre of mass is

44. Two particles inside a system exert equal and opposite forces on each other along the same line. In the equation for the whole system, these two forces

45. Study the table and select the row with the correct unit-vector cross product.

46. A pair of equal and opposite parallel forces acting at different points on a rigid body forms a couple. The main effect of a couple is to produce

47. A uniform solid cylinder rolls without slipping with centre-of-mass speed . If , its total kinetic energy is

48. The rolling-without-slipping condition between the centre-of-mass speed , radius , and angular speed is

49. If units, units, and the angle between and is , then is

50. A horizontal force is applied at the edge of a door. It opens the door most effectively when the force is applied