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Uniform Circular Motion & Centripetal Acceleration — NEET Physics MCQs with Solutions

Free NEET Physics Uniform Circular Motion & Centripetal Acceleration MCQs with step-by-step solutions (8 questions). Part of Circular Motion. Practise online on Prepizo — no login needed.

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Questions with solutions

Q1 — Uniform Circular Motion & Centripetal Acceleration · easy · theory
In uniform circular motion, which quantity remains constant?
A. Linear momentum
B. Velocity
C. Speed (and kinetic energy)  ✓ Correct
D. Acceleration (as a vector)
Solution: Speed is fixed but the DIRECTIONS of v⃗, a⃗ and p⃗ rotate continuously — none of those vectors is constant.
Q2 — Uniform Circular Motion & Centripetal Acceleration · medium · theory
In UCM, the work done by the centripetal force in one full revolution is:
A. Negative
B. 2πr × F
C. mv²/r × 2πr
D. Zero  ✓ Correct
Solution: F ⊥ v at every instant, so no work is ever done; KE stays constant, consistent with constant speed.
Q3 — Uniform Circular Motion & Centripetal Acceleration · easy · numerical
A particle moves at 6 m/s on a circle of radius 3 m. Its centripetal acceleration is:
A. 2 m/s²
B. 6 m/s²
C. 12 m/s²  ✓ Correct
D. 18 m/s²
Solution: a_c = v²/r = 36/3 = 12 m/s².
Q4 — Uniform Circular Motion & Centripetal Acceleration · medium · numerical
A satellite completes a circular orbit of radius 4 m (model) in 2 s. Its centripetal acceleration is (π² ≈ 10):
A. ≈ 20 m/s²
B. ≈ 80 m/s²
C. ≈ 4 m/s²
D. ≈ 40 m/s²  ✓ Correct
Solution: ω = 2π/T = π rad/s; a_c = ω²r = π²×4 ≈ 40 m/s².
Q5 — Uniform Circular Motion & Centripetal Acceleration · hard · numerical
If the speed of a particle in UCM doubles and the radius is halved, the centripetal acceleration becomes:
A. 4 times
B. 8 times  ✓ Correct
C. Unchanged
D. 2 times
Solution: a = v²/r → (2v)²/(r/2) = 8v²/r — an 8-fold increase.
Q6 — Uniform Circular Motion & Centripetal Acceleration · medium · numerical
Two particles ride at radii r and 2r on the same rotating disc. The ratio of their centripetal accelerations (inner : outer) is:
A. 1 : 4
B. 1 : 1
C. 1 : 2  ✓ Correct
D. 2 : 1
Solution: Same ω on a rigid disc ⇒ a = ω²r ∝ r ⇒ ratio 1:2. Trap: using a = v²/r with the same v is wrong here.
Q7 — Uniform Circular Motion & Centripetal Acceleration · easy · numerical
A cyclist rounds a circular track of radius 20 m at 10 m/s. The required centripetal acceleration is:
A. 2 m/s²
B. 10 m/s²
C. 0.5 m/s²
D. 5 m/s²  ✓ Correct
Solution: a_c = v²/r = 100/20 = 5 m/s².
Q8 — Uniform Circular Motion & Centripetal Acceleration · medium · numerical
A stone on a 1 m string makes 60 rpm in a horizontal circle. Its centripetal acceleration is (π² ≈ 10):
A. ≈ 40 m/s²  ✓ Correct
B. ≈ 10 m/s²
C. ≈ 4 m/s²
D. ≈ 60 m/s²
Solution: ω = 2π×60/60 = 2π rad/s; a = ω²r = 4π² ≈ 40 m/s².