Question

10. A coil has 400 turns and self-inductance 4.80 mH. The current in the coil varies with time according to i=(680mA)cos(att/0.0250s). (a) What is the maximum emf induced in the coil? (b) What is the maximum average flux through each turn of the coil? (c) At t= 0.0180 s, what is the magnitude of the induced emf?

Answer 1

- a) according to the condition given in question We have e = Lei * = 48x10 % 68 oma) co s 6v+/0.05) e = 4.8x10 x 680x10²x II sin It 0.025 0.025 e ma x = 4, X 680 XI b X x40x) [emax = 0.41 Volts b) Now fiux through each turn = ¢ 1. dt No a Li N° = 418 x10 680x18 208 Tt . 0.025. 400&max = 418 x 680 x 100 A max = 4.8 X 680 x16" uoo. &max = 8,6x15 wb

c) We know that e = may sin" Tt 0.025 e = 0,4 sin x 01018 5 0.025 e = 0.4 sin 0.72 TT e = 0.94 x 0.034 e = 0.01156 volts