Description: Practice Class 11 Physics Chapter 4 Rotational and Circular Motion MCQs according to the FBISE HSSC-I syllabus. These exam-oriented questions cover angular displacement, angular velocity, angular acceleration, circular motion, centripetal acceleration and force, satellites, torque, moment of inertia, angular momentum, rotational kinetic energy, and conservation of angular momentum.
2. One complete revolution is equal to how many radians?
A) π/2 B) π C) 3π/2 D) 2π
3. The relation between arc length s, radius r and angular displacement θ is:
A) s = rθ B) s = r/θ C) s = θ/r D) s = r + θ
4. If a wheel rotates through 180°, its angular displacement in radians is:
A) π/4 B) π/2 C) π D) 2π
5. Angular velocity is defined as the rate of change of:
A) angular displacement B) linear displacement C) force D) momentum
6. The SI unit of angular velocity is:
A) m/s B) rad/s C) rad/s² D) N m
7. The SI unit of angular acceleration is:
A) rad/s B) m/s² C) rad/s² D) N m
8. For a point moving in a circle, the relation between linear speed v and angular speed ω is:
A) v = ω/r B) v = r/ω C) v = r + ω D) v = rω
9. The angular speed of an object completing one revolution in time T is:
A) ω = 2π/T B) ω = T/2π C) ω = 2πT D) ω = T + 2π
10. A wheel rotates at 5 revolutions per second. Its angular speed is:
A) 5π rad/s B) 10 rad/s C) 10π rad/s D) 20π rad/s
11. Tangential speed of a point on a rotating wheel increases when its:
A) radius decreases at constant ω B) angular speed increases C) mass decreases D) moment of inertia decreases
12. For uniform circular motion, the magnitude of velocity is:
A) constant B) zero C) increasing continuously D) decreasing continuously
13. In uniform circular motion, the direction of velocity is:
A) radially inward B) radially outward C) always upward D) tangential to the path
14. Centripetal acceleration is directed:
A) along the tangent B) away from the centre C) towards the centre D) opposite to velocity
15. The magnitude of centripetal acceleration is:
A) a = vr B) a = v²/r C) a = r/v² D) a = v/r²
16. Using angular speed, centripetal acceleration can be written as:
A) a = rω² B) a = r/ω² C) a = ω/r² D) a = rω
17. The centripetal force required for circular motion is:
A) F = mv/r B) F = mr/v² C) F = mω/r D) F = mv²/r
18. If the speed of an object moving in a circle is doubled while radius remains constant, centripetal force becomes:
A) half B) double C) four times D) unchanged
19. If the radius of circular motion is doubled while speed remains constant, centripetal acceleration becomes:
A) half B) double C) four times D) unchanged
20. A car moving around a level circular road is mainly provided centripetal force by:
A) its weight B) friction between tyres and road C) engine power alone D) air resistance
21. A satellite in a circular orbit is kept in orbit by:
A) magnetic force B) friction C) normal force D) gravitational force
22. An orbiting satellite appears weightless because it is:
A) outside Earth’s gravity B) at rest in space C) in continuous free fall D) without mass
23. Artificial gravity in a rotating spacecraft can be produced by:
A) rotation of the spacecraft B) removing all air C) stopping its rotation D) reducing its mass to zero
24. For a body rotating about a fixed axis, angular displacement is analogous to:
A) force B) linear displacement C) mass D) power
25. Torque is the turning effect of a:
A) mass B) velocity C) force D) temperature
26. The magnitude of torque is given by:
A) τ = Fr B) τ = F/r C) τ = r/F D) τ = rF sinθ
27. Torque is maximum when the angle between r and F is:
A) 90° B) 0° C) 30° D) 180°
28. Torque is zero when the line of action of the force:
A) is perpendicular to the radius B) passes through the axis of rotation C) is at 45° to the radius D) is tangent to a different circle
29. The SI unit of torque is:
A) joule/second B) newton/second C) newton metre D) kilogram metre
30. For the same force, torque can be increased by:
A) increasing the perpendicular distance from the axis B) decreasing the lever arm C) applying the force through the axis D) decreasing the force to zero
31. Moment of inertia is a measure of an object’s resistance to change in:
A) linear velocity B) temperature C) mass D) rotational motion
32. For a system of particles, moment of inertia about an axis is:
A) I = Σmr B) I = Σmr² C) I = Σm/r² D) I = Σr/m
33. The SI unit of moment of inertia is:
A) kg m² B) kg/m² C) N m D) kg m/s
34. For a point mass m at distance r from an axis, its moment of inertia is:
A) I = mr B) I = m/r² C) I = mr² D) I = r²/m
35. If the distance of a point mass from the rotation axis is doubled, its moment of inertia becomes:
A) half B) double C) three times D) four times
36. The rotational form of Newton’s second law is:
A) τ = I/α B) τ = Iα C) τ = α/I D) τ = I + α
37. If the net torque on a body is doubled while its moment of inertia remains constant, angular acceleration:
A) doubles B) halves C) becomes four times D) remains unchanged
38. Angular momentum of a rigid body rotating about a fixed axis is:
A) L = I/ω B) L = I + ω C) L = Iω D) L = ω/I
39. The SI unit of angular momentum is:
A) N/s B) kg/m C) rad/s D) kg m²/s
40. If no external torque acts on a system, its total angular momentum:
A) remains conserved B) always increases C) always decreases D) becomes zero
41. An ice skater spins faster when she pulls her arms inward because her:
A) mass increases B) moment of inertia decreases C) angular momentum disappears D) torque from gravity increases
42. A flywheel is commonly used to:
A) eliminate all friction B) convert mass into energy C) store rotational energy D) stop rotation instantly
43. A gyroscope can be useful in navigation because of the:
A) conservation of linear speed B) law of gravitation only C) conservation of mass D) conservation of angular momentum
44. For a rotating rigid body, rotational kinetic energy is:
A) K = 1/2 Iω² B) K = Iω C) K = 1/2 Iω D) K = I/ω²
45. If angular speed is doubled, rotational kinetic energy becomes:
A) half B) double C) four times D) unchanged
46. A force produces no torque about an axis when its line of action:
A) is perpendicular to the axis B) passes through the axis C) is tangent to the circle D) is parallel to the radius
47. A larger steering wheel makes steering easier because it provides a larger:
A) angular acceleration B) mass C) angular displacement D) torque for the same force
48. For a uniform circular motion, the centripetal force does no work because it is:
A) perpendicular to instantaneous velocity B) parallel to velocity C) opposite to velocity D) zero
49. A body moving in a circle with constant speed has:
A) zero acceleration B) constant velocity C) constant magnitude of velocity but changing direction D) zero centripetal force
50. If the angular velocity of a rotating object is constant, its angular acceleration is:
FBISE syllabus: National Curriculum of Pakistan 2022–23, FBISE Assessment Framework for Physics Grade XI.
Content area: Domain B – Mechanics
Relevant SLOs: P-11-B-07 to P-11-B-21
Alignment: Radians and angular motion; angular-motion equations; centripetal force and circular motion; weightlessness and artificial gravity; moment of inertia, torque, angular acceleration and conservation of angular momentum.
Assessment note: The FBISE framework distinguishes summative SLOs used in the final examination from formative SLOs used in teaching-learning. MCQs on this page should be treated as practice aligned to the listed content/SLOs, not as a reproduction of the official FBISE paper.