Question

Two long, straight, parallel conductors carry steady currents in opposite directions. Explain the nature of the force of interaction between them. Obtain an expression for the magnitude of the force between the two conductors. Hence define one ampere.

Obtain an expression for the torque τ acting on a current carrying loop in a uniform magnetic field B. Draw the necessary diagram.

A particle of mass m and charge q is moving with a velocity v in a magnetic field B as shown in the figure. Show that it follows a helical path. Hence, obtain its frequency of revolution.

In a hydrogen atom, the electron moves in an orbit of radius 2 Å making 8 × 10¹⁴ revolutions per second. Find the magnetic moment associated with the orbital motion of the electron.