posted by Joanna on .
1. A closed magnetic circuit of cast steel contains a 6cm long path of cross sectional area 1cm square and a 2cm part of cross sectional area of 0.5cm square. A coil of 200 turns is wound around the 6cm length of the circuit and a current of 0.4ampere flows. Determine the flux density in the 2cm path if the relative permeability of cast steel is 750.
2. A flux of 25m wb links of a 1500turns coil when a current of 3ampere passes through the coil, calculate
i. The inductance of the coil
ii. The average emf induced if the current falls to 0 in 15ms.
750*200* 0.4/6 10,000T