Uniform Circular Motion — MH-CET Physics MCQs with Solutions
Free MH-CET Physics Uniform Circular Motion MCQs with step-by-step solutions (20 questions). Part of Motion in a Plane (Std 11). Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Uniform Circular Motion · easy · theory
In uniform circular motion, the quantity that remains constant is the:
A. Momentum
B. Speed ✓ Correct
C. Acceleration
D. Velocity
Solution: The direction of motion changes continuously, so velocity, acceleration and momentum are all changing vectors.
Q2 — Uniform Circular Motion · easy · theory
The centripetal acceleration of a body in uniform circular motion is directed:
A. Towards the centre of the circle ✓ Correct
B. Away from the centre
C. Opposite to the motion
D. Along the tangent
Solution: It continually turns the velocity vector without changing its magnitude.
Q3 — Uniform Circular Motion · easy · theory
The centripetal acceleration of a body moving at speed $v$ in a circle of radius $r$ is:
A. $vr$
B. $\dfrac{v}{r}$
C. $\dfrac{v^2}{r}$ ✓ Correct
D. $\dfrac{v^2}{r^2}$
Solution: It may also be written $\omega^2r$ using the angular velocity.
Q4 — Uniform Circular Motion · medium · theory
The period of revolution of a body in uniform circular motion is:
A. $\dfrac{v}{2\pi r}$
B. $\dfrac{2\pi r}{v}$ ✓ Correct
C. $2\pi rv$
D. $\dfrac{2\pi}{r}$
Solution: It is the time taken to travel one full circumference.
Q5 — Uniform Circular Motion · easy · theory
The angular velocity of a body in uniform circular motion is related to its period by:
A. $\omega = \dfrac{T}{2\pi}$
B. $\omega = 2\pi T$
C. $\omega = \dfrac{1}{T}$
D. $\omega = \dfrac{2\pi}{T}$ ✓ Correct
Solution: One revolution corresponds to an angle of $2\pi$ radian.
Q6 — Uniform Circular Motion · easy · theory
The relation between linear speed and angular velocity in circular motion is:
A. $v = \dfrac{\omega}{r}$
B. $v = \dfrac{r}{\omega}$
C. $v = \omega r$ ✓ Correct
D. $v = \omega^2 r$
Solution: A point further from the axis moves faster for the same angular velocity.
Q7 — Uniform Circular Motion · easy · theory
The centripetal force needed to keep a body of mass $m$ in a circle is:
A. $\dfrac{mv^2}{r}$, directed towards the centre ✓ Correct
B. $\dfrac{mv}{r}$, towards the centre
C. $mvr$, along the tangent
D. $\dfrac{mv^2}{r}$, directed away from the centre
Solution: It is supplied by some real agency such as tension, friction or gravity.
Q8 — Uniform Circular Motion · medium · theory
In uniform circular motion, the work done by the centripetal force over one revolution is:
A. Equal to the kinetic energy
B. Negative
C. Zero ✓ Correct
D. Maximum
Solution: The force is everywhere perpendicular to the displacement.
Q9 — Uniform Circular Motion · easy · numerical
A body moves in a circle of radius $5\text{ m}$ at $10\text{ m/s}$. Its centripetal acceleration is:
A. $100\text{ m/s}^2$
B. $2\text{ m/s}^2$
C. $20\text{ m/s}^2$ ✓ Correct
D. $50\text{ m/s}^2$
Solution: $a_c = \dfrac{v^2}{r} = \dfrac{100}{5} = 20\text{ m/s}^2$.
Q10 — Uniform Circular Motion · easy · numerical
A body moves in a circle of radius $4\text{ m}$ at $8\text{ m/s}$. Its centripetal acceleration is:
A. $16\text{ m/s}^2$ ✓ Correct
B. $2\text{ m/s}^2$
C. $32\text{ m/s}^2$
D. $64\text{ m/s}^2$
Solution: $a_c = \dfrac{64}{4} = 16\text{ m/s}^2$.
Q11 — Uniform Circular Motion · easy · numerical
A body moves in a circle of radius $0.5\text{ m}$ with angular velocity $10\text{ rad/s}$. Its linear speed is:
A. $0.05\text{ m/s}$
B. $5\text{ m/s}$ ✓ Correct
C. $20\text{ m/s}$
D. $10\text{ m/s}$
Solution: $v = \omega r = 10 \times 0.5 = 5\text{ m/s}$.
Q12 — Uniform Circular Motion · hard · numerical
A body moves in a circle of radius $5\text{ m}$ at $10\text{ m/s}$. Its period of revolution is approximately:
A. $3.14\text{ s}$ ✓ Correct
B. $0.5\text{ s}$
C. $6.28\text{ s}$
D. $2\text{ s}$
Solution: $T = \dfrac{2\pi r}{v} = \dfrac{2\pi \times 5}{10} = \pi \approx 3.14\text{ s}$.
Q13 — Uniform Circular Motion · medium · numerical
A body revolves at $2$ revolutions per second. Its angular velocity is:
A. $\pi\text{ rad/s}$
B. $2\text{ rad/s}$
C. $4\pi\text{ rad/s}$ ✓ Correct
D. $2\pi\text{ rad/s}$
Solution: $\omega = 2\pi n = 2\pi \times 2 = 4\pi\text{ rad/s}$.
Q14 — Uniform Circular Motion · medium · numerical
A body moves in a circle of radius $2\text{ m}$ with angular velocity $5\text{ rad/s}$. Its centripetal acceleration is:
A. $100\text{ m/s}^2$
B. $25\text{ m/s}^2$
C. $50\text{ m/s}^2$ ✓ Correct
D. $10\text{ m/s}^2$
Solution: $a_c = \omega^2r = 25 \times 2 = 50\text{ m/s}^2$.
Q15 — Uniform Circular Motion · easy · numerical
If the speed of a body in circular motion is doubled at the same radius, its centripetal acceleration becomes:
A. Unchanged
B. Four times as large ✓ Correct
C. Twice as large
D. Half as large
Solution: $a_c \propto v^2$.
Q16 — Uniform Circular Motion · easy · numerical
If the radius of the circular path is doubled at the same speed, the centripetal acceleration becomes:
A. Four times as large
B. Twice as large
C. Half as large ✓ Correct
D. Unchanged
Solution: $a_c = \dfrac{v^2}{r} \propto \dfrac{1}{r}$.
Q17 — Uniform Circular Motion · medium · numerical
A body of mass $2\text{ kg}$ moves in a circle of radius $2\text{ m}$ at $4\text{ m/s}$. The centripetal force is:
A. $16\text{ N}$ ✓ Correct
B. $8\text{ N}$
C. $4\text{ N}$
D. $32\text{ N}$
Solution: $F = \dfrac{mv^2}{r} = \dfrac{2 \times 16}{2} = 16\text{ N}$.
Q18 — Uniform Circular Motion · medium · numerical
A body completes one revolution in $4\text{ s}$. Its angular velocity is:
A. $\dfrac{\pi}{2}\text{ rad/s}$ ✓ Correct
B. $2\pi\text{ rad/s}$
C. $\dfrac{1}{4}\text{ rad/s}$
D. $4\pi\text{ rad/s}$
Solution: $\omega = \dfrac{2\pi}{T} = \dfrac{2\pi}{4} = \dfrac{\pi}{2}\text{ rad/s}$.
Q19 — Uniform Circular Motion · medium · numerical
A wheel rotates at $300$ revolutions per minute. Its angular velocity is:
A. $600\pi\text{ rad/s}$
B. $300\text{ rad/s}$
C. $5\pi\text{ rad/s}$
D. $10\pi\text{ rad/s}$ ✓ Correct
Solution: $\omega = \dfrac{2\pi \times 300}{60} = 10\pi\text{ rad/s}$.
Q20 — Uniform Circular Motion · easy · numerical
A car rounds a bend of radius $100\text{ m}$ at $20\text{ m/s}$. Its centripetal acceleration is:
A. $0.2\text{ m/s}^2$
B. $40\text{ m/s}^2$
C. $4\text{ m/s}^2$ ✓ Correct
D. $2000\text{ m/s}^2$
Solution: $a_c = \dfrac{400}{100} = 4\text{ m/s}^2$.