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.

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.

The strength of the magnetic field along solenoid having 5000 turns per meter is 3.14 xx 10^-2 T . The current flowing through the solenoid is

A closely wound solenoid of 800 turns and area of cross section 2.5 xx 10^-4 m^2 carries a current of 3.0 A. Explain the sense in which the solenoid acts like a bar magnet. What is its associated magnetic moment ?

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 closely wound solenoid of 2000 turns and area of cross-section 1.6 xx 10^-4 m^2 ,carrying a current of 4.0 A,is suspended through its centre allowing it to turn in a horizontal plane. What are the force and torque on the solenoid if a uniform horizontal magnetic field of 7.5 xx 10^-2 T is set up at an angle of 30^@ with the axis of the solenoid ?

A long solenoid carrying a current produces a magnetic field B along the axis. If the number of turns per cm is tripled and the current is halved, then the new value of the magnetic field will be

A very long solenoid has 8400 winding and a length of 7m. If the field inside is 2pi xx 10^-3 T , the current in the windings is about [ mu_0 = 4pi xx 10^-7 T m//A ]

The electric current in a circular coil of two turns produced a magnetic induction of 0.2 T at its centre. The coil is unwound and then rewound into a circular coil of four turns. If same current flows in the coil, the magnetic induction at the centre of the coil now is