Variable Angular Acceleration & Non-Uniform Motion — NEET Physics MCQs with Solutions
Free NEET Physics Variable Angular Acceleration & Non-Uniform Motion MCQs with step-by-step solutions (8 questions). Part of Circular Motion. Practise online on Prepizo — no login needed.
▶ Practise Variable Angular Acceleration & Non-Uniform Motion online (free)
Questions with solutions
Q1 — Variable Angular Acceleration & Non-Uniform Motion · easy · theory
In NON-uniform circular motion, the net acceleration is:
A. Purely tangential
B. Purely radial
C. Zero
D. Neither purely radial nor purely tangential — it has both components ✓ Correct
Solution: Speed changes (a_t ≠ 0) while direction changes (a_c ≠ 0): the total acceleration tilts away from the radius.
Q2 — Variable Angular Acceleration & Non-Uniform Motion · medium · theory
The angular kinematics equations (ω = ω₀ + αt, etc.) may be used only when:
A. The motion is circular
B. ω is small
C. The angular acceleration α is constant ✓ Correct
D. The radius is constant
Solution: They are the rotational analogues of constant-acceleration kinematics; for α(t) or α(θ) you must integrate.
Q3 — Variable Angular Acceleration & Non-Uniform Motion · easy · numerical
A wheel's angular speed grows as ω = 4t (rad/s). Its angular acceleration and the angle swept in 2 s are:
A. 4 rad/s² and 8 rad ✓ Correct
B. 8 rad/s² and 8 rad
C. 2 rad/s² and 4 rad
D. 4 rad/s² and 16 rad
Solution: α = dω/dt = 4 rad/s²; θ = ∫ω dt = 2t² = 8 rad at t = 2 s.
Q4 — Variable Angular Acceleration & Non-Uniform Motion · medium · numerical
A flywheel has α = 6t (rad/s²) and starts from rest. Its angular speed at t = 2 s is:
A. 12 rad/s ✓ Correct
B. 24 rad/s
C. 3 rad/s
D. 6 rad/s
Solution: ω = ∫6t dt = 3t² = 12 rad/s. Trap: NOT ω = αt (α is not constant).
Q5 — Variable Angular Acceleration & Non-Uniform Motion · hard · numerical
A particle's angular acceleration depends on angle as α = 4θ (rad/s²), starting from rest at θ = 0. Its angular speed at θ = 2 rad is:
A. 16 rad/s
B. 8 rad/s
C. 2√2 rad/s
D. 4 rad/s ✓ Correct
Solution: ω dω = α dθ ⇒ ω²/2 = ∫₀² 4θ dθ = 8 ⇒ ω = 4 rad/s.
Q6 — Variable Angular Acceleration & Non-Uniform Motion · medium · numerical
A fan slows uniformly from 30 rad/s to rest in 15 s. The total angle turned during the stop is:
A. 225 rad ✓ Correct
B. 112.5 rad
C. 450 rad
D. 30 rad
Solution: θ = (ω₀ + 0)/2 × t = 15×15 = 225 rad.
Q7 — Variable Angular Acceleration & Non-Uniform Motion · easy · numerical
A wheel accelerates uniformly from 10 rad/s to 30 rad/s in 5 s. Its angular acceleration is:
A. 2 rad/s²
B. 4 rad/s² ✓ Correct
C. 8 rad/s²
D. 6 rad/s²
Solution: α = Δω/Δt = 20/5 = 4 rad/s².
Q8 — Variable Angular Acceleration & Non-Uniform Motion · medium · numerical
A motor reaches 1200 rpm from rest in 4 s (uniformly). The number of revolutions made in this time is:
A. 40 ✓ Correct
B. 10
C. 80
D. 20
Solution: n_avg = 600 rpm = 10 rev/s over 4 s ⇒ 40 revolutions.