Moving Charges And MagnetismClass 12 Physics Assertion & Reason Questions

Assertion (A): The magnetic force does no work on a moving charged particle.

Reason (R): The kinetic energy of a charged particle moving through a uniform magnetic field remains constant.

Assertion (A): To convert a galvanometer into an ammeter, a small resistance called a shunt is connected in parallel with the galvanometer coil.

Reason (R): The shunt resistance provides a path for the majority of the total current to bypass the galvanometer, thereby increasing its range and protecting it from damage.

Assertion (A): The cyclotron frequency is independent of the speed of the charged particle.

Reason (R): The magnetic force provides the centripetal force, mv^2/r = qvB, which simplifies to an angular frequency \omega = qB/m that does not depend on velocity v.