Calculate the current required in a 500 turn coil to

Question

1. Calculate the current required in a 500 turn coil to produce an electric field strength of 4000 At/m in an iron circuit of mean length 25 cm.

2. A 400 turn coil is wound onto an iron toroid of mean length 18 cm and uniform csa 4.5 cm². If a coil current of 2.25 A results in a flux of 0.5 mWb, determine

(a) the mmf,

(b) the flux density,

(c) the magnetic field strength.