In a circuit with an inductance of 0.2 g, the current strength changes according to the law I = 2t2 + 1 (A).

In a circuit with an inductance of 0.2 g, the current strength changes according to the law I = 2t2 + 1 (A). Determine the average value of the EMF of self-induction for the third second of observation.

Data: L (inductance of the specified circuit) = 0.2 H; I (law of current change) = 2t ^ 2 + 1.

1) Current change function: ΔI / Δt = (2t ^ 2 + 1) ‘= 2 * 2t = 4t.

2) Change in current in the third second: ΔI / Δt (3) = 4t ^ 3 – 4t ^ 2 = 4 * 3 – 4 * 2 = 4 A / s.

3) EMF value of self-induction: εi = L * ΔI / Δt (3) = 0.2 * 4 = 0.8 V.

Answer: The EMF value of self-induction for the past third second is 0.8 V.