Conical Pendulum & Rotating Systems — NEET Physics MCQs with Solutions
Free NEET Physics Conical Pendulum & Rotating Systems 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 — Conical Pendulum & Rotating Systems · easy · theory
In a conical pendulum, the centripetal force on the bob is supplied by:
A. Friction
B. The weight of the bob
C. The vertical component of the tension
D. The horizontal component of the string tension (T sinθ) ✓ Correct
Solution: T cosθ = mg balances gravity; T sinθ = mω²r drives the circular motion.
Q2 — Conical Pendulum & Rotating Systems · medium · theory
The period of a conical pendulum of length L at semi-vertical angle θ is:
A. 2π√(L sinθ/g)
B. 2π√(L/g)
C. 2π√(g/L cosθ)
D. 2π√(L cosθ/g) ✓ Correct
Solution: T = 2π√(h/g) with h = L cosθ (height of the support above the circle's plane). Note it is SHORTER than the simple-pendulum period.
Q3 — Conical Pendulum & Rotating Systems · easy · numerical
A conical pendulum's bob of mass 2 kg circles with the string at 60° to the vertical (cos60° = 0.5). The string tension is:
A. 34.6 N
B. 40 N ✓ Correct
C. 20 N
D. 10 N
Solution: T cosθ = mg ⇒ T = 20/0.5 = 40 N.
Q4 — Conical Pendulum & Rotating Systems · medium · numerical
A conical pendulum has L cosθ = 0.4 m. Its angular speed is:
A. √5 rad/s
B. 25 rad/s
C. 5 rad/s ✓ Correct
D. 2.5 rad/s
Solution: ω = √(g/L cosθ) = √(10/0.4) = √25 = 5 rad/s.
Q5 — Conical Pendulum & Rotating Systems · hard · numerical
A 1 kg bob on a 2 m string moves as a conical pendulum with a period of 2 s (π² ≈ 10). The semi-vertical angle satisfies cosθ =
A. 0.71 (θ = 45°)
B. 0.25
C. 0.5 (θ = 60°) ✓ Correct
D. 0.87 (θ = 30°)
Solution: T = 2π√(Lcosθ/g) ⇒ cosθ = gT²/(4π²L) = 10×4/(40×2) = 0.5 ⇒ θ = 60°.
Q6 — Conical Pendulum & Rotating Systems · medium · numerical
A bob circles as a conical pendulum with radius 0.3 m and speed 3 m/s. The tangent of the string's angle with the vertical is:
A. 0.9
B. 3 ✓ Correct
C. 1
D. 0.3
Solution: tanθ = v²/rg = 9/(0.3×10) = 3 ⇒ θ ≈ 72°.
Q7 — Conical Pendulum & Rotating Systems · easy · numerical
A conical pendulum bob of mass 0.4 kg hangs at 45° to the vertical while circling. The tension is (√2 ≈ 1.41):
A. 4 N
B. ≈ 2.8 N
C. ≈ 5.7 N ✓ Correct
D. 8 N
Solution: T = mg/cos45° = 4/0.707 ≈ 5.7 N.
Q8 — Conical Pendulum & Rotating Systems · medium · numerical
A conical pendulum has its support 0.9 m above the plane of the bob's circle (h = L cosθ = 0.9 m, π² ≈ 10). Its period is:
A. ≈ 3.8 s
B. ≈ 0.9 s
C. ≈ 1.2 s
D. ≈ 1.9 s ✓ Correct
Solution: T = 2π√(h/g) = 2π√0.09 = 2π×0.3 ≈ 1.9 s.