Answer to Question 7

A coil has 500 turns and is known to have an inductance of 0.35 H.

(a) Calculate the reluctance.

(b) Calculate the flux if the current is 100 mA.

Formula:

(a) S = (500 turns)^{2} ÷ 0.35 H = 7.1 × 10^{5} H^{-1}

(b) F = NI/S = (500 turns × 0.10 A) ÷ 7.1 × 10^{5} H^{-1} = 7.0 × 10^{-5} Wb