Four equal and parallel forces are acting on a rod (as shown in fig.) at distances of $20 \,cm, 40\, cm, 60\, cm$ and $80\, cm$ respectively from one end of the rod under the influence of these forces the rod -

- A
is at rest

- B
experience a torque

- C
experience a linear motion

- D
experience a torque and also linear motion

A wheel having moment of inertia $2 \;kg \,m ^{2}$ about its vertical axis, rotates at the rate of $60 \;rpm$ about this axis. The torque which can stop the wheel's rotation in one minute would be

- [AIPMT 2004]

A solid cylinder of mass $50\, kg$ and radius $0.5\, m $ is free to rotate about the horizontal axis. A massless string is wound round the cylinder with one end attached to it and other hanging freely. Tension in the string required to produce an angular acceleration of $2$ revolutions $s^{-2}$ is ...... $N$

- [AIPMT 2014]

Two persons of equal height are carrying a long uniform wooden beam of length $\ell $. They are at distance $\frac{\ell }{5}$ and $\frac{\ell }{3}$ . From nearest end of the rod. The ratio of normal reaction at their heads is

What is couple? Give its illustration.

To mop-clean a floor, a cleaning machine presses a circular mop of radius $R$ vertically down with a total force $F$ and rotates it with a constant angular speed about its axis. If the force $F$ is distributed uniformly over the mop and the floor is $\mu $, the torque, applied by the machine on the mop is

- [JEE MAIN 2019]