Question

A current I = 10 sin(100π t) A is passed in first coil, which induces a maximum e.m.f of 5π volt in second coil. The mutual inductance between the coils is ______.

Options

• 10 mH

• 15 mH

• 25 mH

• 5 mH

Answer 1

A current I = 10 sin(100π t) A is passed in first coil, which induces a maximum e.m.f of 5π volt in second coil. The mutual inductance between the coils is 5 mH.

Explanation:

Let I = I₀ sin ωt

where I₀ = 10, ω = 100 π

hen ε = M `("d"  "I")/("d"  "t")`

= M `"d"/("d"  "t")` I₀ sin ωt

= M I₀ω cosωt

∴ ε_max = MI₀ω

5π = M × 10 × 100π

M = 5 mH