In a coil with an inductance of 0.2 mH using a rheostat, the current strength is uniformly increased at a rate of 100 A / s.

In a coil with an inductance of 0.2 mH using a rheostat, the current strength is uniformly increased at a rate of 100 A / s. What is the absolute value of the self-induction EMF (in mV) that occurs in the coil?

The self-induction EMF arising in the coil can be calculated using the formula:

εis = – L * ΔФ / Δt, where L is the inductance of the coil (L = 0.2 mH = 0.2 * 10-3 H), ΔФ / Δt is the rate of change of the magnetic flux.

If the magnetic field in the coil is created by current, then Ф ~ В ~ I and the formula will take the form:

εis = – L * ΔI / Δt, where ΔI / Δt = 100 A / s.

Let’s calculate the absolute value of the EMF of self-induction in the coil:

εis = L * ΔI / Δt = 0.2 * 10-3 * 100 = 0.02 V.

Answer: The absolute value of the EMF of self-induction in the coil is 0.02 V.