Explanation

To find the self-inductance of a coil, we can use the formula:

L = (ΔΦ / ΔI)

Where:

L is the self-inductance in Henry (H),

ΔΦ is the change in magnetic flux in Weber (Wb),

and ΔI is the change in current in Ampere (A).

In this case, the current changes from 5A to 0A (nil) in 5 seconds. (ΔI) is therefore 5A - 0A = 5A.

To find the change in (ΔΦ), we can use Faraday's law of electromagnetic induction

ΔΦ = L * ΔI

Since the current changes from 5A to 0A in 5 seconds, the rate of  (ΔI) is 5A / 5s = 1A/s.

Substituting the values into the equation:

ΔΦ = L * ΔI

500 V = L * 1 A/s

Since the (V) is equal to  (L) and  (ΔI), we can rewrite the equation as:

L = 500 V / 1 A/s

Simplifying the equation gives us:

L = 500 H

Therefore, the self-inductance of the coil is 500 Henry (H).