Q.31 Give an example of a situation in which an applied force does not result in a change in kinetic energy.


Hint: If force is applied normal to the velocity then work done by the force is zero.
Step 1: Interpret the case when a charged particle moves in a uniform normal magnetic field.

When a charged particle moves in a uniform normal magnetic field, the path of the particle is circular, as the given field is uniform hence, the radius of the circular path is also constant.

As the force is central and movement is tangential work done by the force is zero. As speed is also constant we can say that K = 0.