The current decays from 5A to 2A in 0.01s in a coil. The emf induced in a coil nearby it is 30V. Calculate the mutual inductance of the coil.

To determine the mutual inductance (M) between two coils, we can use the formula:

Induced EMF = M × (ΔI / Δt)

Where:

• Induced EMF (E) = 30 V
• Change in current (ΔI) = Initial current - Final current = 5 A - 2 A = 3 A
• Change in time (Δt) = 0.01 s

Rearranging the formula to solve for M:

M = (E × Δt) / ΔI

Substituting the given values:

M = (30 × 0.01) / 3 = 0.3 / 3 = 0.1 H

Therefore, the mutual inductance of the coil is 0.1 henry (H).