MCQ
A constant torque acting on a uniform circular wheel changes its angular momentum from L to 4L in 4 seconds. The magnitude of this torque is:
  • A
    $\frac{3\text{L}}{4}$
  • B
    4L
  • C
    L
  • D
    12L

Answer

  1. $\frac{3\text{L}}{4}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Two astronauts are floating in gravitational free space after having lost contact with their spaceship. The two will 
A simple pendulum has time period T. The bob is given charge and surface below it is given positive charge. The new time period will be:
A body of mass $4 \mathrm{~kg}$ experiences two forces $\overrightarrow{\mathrm{F}}_1=5 \hat{\mathrm{i}}+8 \hat{\mathrm{j}}+7 \hat{\mathrm{k}}$ and $\overrightarrow{\mathrm{F}}_2=3 \hat{\mathrm{i}}-4 \hat{\mathrm{j}}-3 \hat{\mathrm{k}}$. The acceleration acting on the body is :
A body of mass $m$  starts moving from rest along $x-$ axis so that its velocity varies as $v = a\sqrt s$ where $a$ is a constant and $s$  is the distance covered by the body. The total work done by all the forces acting on the body in the first second after the start of the motion is
A trolley is carrying a box on its surface having coefficient of static friction equal to 0.3. Now the trolley starts moving with increasing acceleration. Find the maximum acceleration of the trolley so that the box does not slide back on the trolley.
A block of $\sqrt{3}\,kg$ is attached to a string whose other end is attached to the wall. An unknown force $F$ is applied so that the string makes an angle of $30^{\circ}$ with the wall. The tension $T$ is $...........\,N$ :(Given $g =10\,ms ^{-2}$ )
The acceleration $'a'$ in $m/{s^2}$ of a particle is given by $a = 3{t^2} + 2t + 2$ where $t$ is the time. If the particle starts out with a velocity $u = 2\,m/s$ at $t = 0$, then the velocity at the end of $2$ second is.......$m/s$
In the motion of a projectile freely under gravity, its
On the basis of dimensions, decide which of the following relations for the displacement of a particle undergoing simple harmonic motion is not correct:

  1. $\text{y}=\frac{\text{a}\sin2\pi\text{t}}{\text{T}}.$

  2. $\text{y}=\text{a}\sin\text{vt}.$

  3. $\text{y}=\frac{\text{a}}{\text{T}}\sin\Big(\frac{\text{t}}{\text{a}}\Big).$

  4. $\text{y}=\text{a}\sqrt{2}\Big(\sin\frac{2\pi\text{t}}{\text{T}}-\cos\frac{2\pi\text{t}}{\text{T}}\Big).$

A motor boat is travelling with a speed of $3.0 m/sec$. If the force on it due to water flow is $500 N$, the power of the boat is