A bar magnet has coercivity `4xx10^(3) Am^(-1) `it is desired to demagnetize it by inserting it inside a solenoid 12cm long and has 60 turns the current that should be sent through the solenoid.

An iron rod of volume 10^-4m^3 and relative permeability 1000 is placed inside a long solenoid wound with 5 turns/cm. If a current of 0.5A is passed through the solenoid, find the magnetic moment of the rod.

There is a magnetic material of coericivty 2 xx 10^3 Am^-1 . What current should flow through a solenoid of length 15 cm havign 150 turns to demagnetise the substance completely?

Figure shows a short solenoid of length 4 cm, radius 2.0 cm and number of turns 100., lying inside on the axis of a long solenoid, 80 cm long and number of turns 1,500. What is the flux through the long solenoid, if a current of 5.0 A flows through the short solenoid? Also obtain the mutual inductance of the two solenoids.

A short bar magnet has a magnetic moment of 0.24 JT^(-1) . Calculate the magnitude of the magnetic field produced by the magnet at a distance of 10 cm from the centre of the magnet, on the axis of the magnet.

A short bar magnet has a magnetic moment of 0.48 J T^-1 . Give the direction and magnitude of the magnetic field produced by the magnet at a distance of 10 cm from the centre of the magnet on the axis.

A closely wound solenoid of 1000 turns and area of cross section 1.4xx10^(-4)m^(2) carrying a current of 3 A is suspended through its centre allowing it to turn in a horizontal plane. The magnetic moment associated with this solenoid

What is the force on a wire of length 4.0 cm placed inside a solenoid near its centre, making an angle 30^@ with its axis? The wire carries a current of 12 A and the magnetic field due to the solenoid has a magntiude of 0.25 T.

A p ermanent magnet is the shape of a thin cylinder of length 10 cm has M=10^6 Am . Calculate the magnetisation current I_M .