Solenoid and Toroid

Magnetic moment for a solenoid and corresponding bar magnet is

(A) : A solenoid tend to contract when a current passes through it. (R) : The magnetic field inside the solenoid is uniform.

(a) A toroidal solenoid with an air core has an average radius of 0.15m, area of cross section 12 xx 10^(-4) m^(2) and 1200 turns. Obtain the self inductance of the toroid. Ignore field variation across the cross section of the toroid. (b) A second coil of 300 turns is wound closely on the toroid above. If the current in the primary coil is increased from zero to 2.0 A in 0.05 s, obtain the induced emf in the secondary coil.

Consider a toroid of circular cross - section of radius b, major radius R much greater than minor radius b, (see diagram) find the total energy stored in magnetic field of toroid -

Self-inductance of a solenoid depend on-

(A) : Solenoid produces uniform magnetic field along its axis. (R) : Field of a solenoid is independent of its radius.

A long solenoid is formed by winding 40 turns//cm The current necessary for 40 mT inside the solenoid will be approximately equal to

A bar magnet is brought near a solenoid as shown in figure. Will the solenoid attract or repel the magnet?

A bar magnet is brought near a solenoid as shown in figure. Will the solenoid attract or repel the magnet?

(a)Using Ampere's circuital law, obtain the expression for the magnetic field due to a long solenoid at a point inside the solenoid on its axis. (b )How is the magnetic field inside a given solenoid made strong?