A toroid of narrow radius of 10cm has 1000 turns of wire for a magnetic field of `5 xx 10^-2 T` along its axis. How much current is required to be passed through the wire?

A 50 m long solenoid has 500 turns and produces a magnetic field of 2.5 xx 10^-4 T at its centre. Find the current in the solenoid.

Magnetic field at a distance 2.4 cm from a long straight wire is 16muT . What must be current through the wire?

A horizontal wire 20 m long extending from east to west is falling with a velocity of 10 m/s normal to the Earth s magnetic field of 0.5 xx 10^-4 T . What is the value of induced emf in the wire?

A winding wire which is used to prepare a solenoid of length 80 cm can bear a maximum cuurent of 10 A. the cross-sectional radius of the solenoid is 3 cm. what should be the length of the winding wire if a magnetiic field of 0.2 T is to be produced at the centre of the solenoid along its axis?

A uniform magnetic field of 1.5 T exists in a cylindrical region of radius 10.0 cm, its direction parallel to the axis along east to west. A wire carrying current of 7.0 A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire. If, the wire intersects the axis .

A current of 10A passes through a coil having 5 turns and produces a magnetic field of magnitude. 5 xx 10^-4T at th e centre of the coil. Calculate the diameter of the coil.

Through a coil of radius 3 cm and 25 turns, a current is passed so as to produce a magnetic induction of 10pi xx 10^-5 wb//m^2 , at a point distant 4 m from the centre of the coil on its axis. Find the current.