Class 11 Physics · Chapter 3 · Test 3
Moment of Inertia
35 MCQs This test covers torque, moment of inertia, the relation τ = Iα, angular momentum L = r × p and L = Iω with related numerical problems. It also covers conservation of angular momentum with its examples (diver, skater, turntable, Earth), flywheels and gyroscopes.
35 questions · 30 min · 35 marks
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Sample questions
The first 5 of 35. Try each one, then tap to see the answer.
Question 1
The torque of a force F acting perpendicular to a rod of length r is:
- Aτ = rF
- Bτ = r/F
- Cτ = F/r
- Dτ = r + F
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Answer: A
Torque is the turning effect of a force and equals the product of r and F.
Question 2
The SI unit of torque is:
- AN s
- BN m
- Ckg m²
- DJ s
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Answer: B
Torque is force times distance so its unit is newton metre.
Question 3
The torque acting on a rotating rigid body is related to angular acceleration by:
- Aτ = I/α
- Bτ = Iω
- Cτ = Iα
- Dτ = α/I
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Answer: C
Multiplying F = ma by r gives τ = (mr²)α = Iα.
Question 4
The rotational analogue of mass in linear motion is:
- Atorque
- Bangular velocity
- Cangular momentum
- Dmoment of inertia
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Answer: D
Moment of inertia plays the same role in rotation as mass does in linear motion.
Question 5
The moment of inertia of a point mass m at distance r from the axis is:
- Amr
- Bmr²
- Cm/r²
- Dm²r
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Answer: B
I = mr² as obtained from τ = mr²α.
More tests in Circular and Rotational Motion
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