Question

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

A circular loop of wire, carrying a current 'I' is lying in xy-plane with its centre coinciding with the origin. It is subjected to a uniform magnetic field pointing along + z-axis. The loop will :

A current carrying circular loop of magnetic moment M⃗ is suspended in a vertical plane in an external magnetic field B⃗ such that its plane is normal to B⃗. The work done in rotating this loop by 45° about an axis perpendicular to B⃗ is closest to :

A galvanometer is converted into a voltmeter of range (0 – V) volt using a resistor of 9900 Ω. If a resistor of 4900 Ω is used, the range becomes half, i.e. (0 – V/2) volt. Calculate : (a) resistance of the galvanometer (b) resistance required to convert it into a voltmeter of range (0 – 2V) volt.