State and explain Maxwell’s right-hand thumb rule.

Two coils $\mathrm{P}$ and $\mathrm{S}$ are wound over the same iron core. Coil $\mathrm{P}$ is connected to battery and key and the coil $\mathrm{S}$ is connected to galvanometer. Write your observation when:

(i) Current in the coil $\mathrm{P}$ is started by closing the key.

(ii) Current continues to flow in the coil $\mathrm{P}$.

(iii) Current in coil $\mathrm{P}$ is stopped by removing the key.

Explain the reason for each observation.