What is the function of an earth wire? Why is it necessary to earth metallic appliances?

When does an electric short circuit occur?

Explain the underlying principle and working of an electric generator by drawing a labeled diagram. What is the function of brushes?

State the rule to determine the direction of an

(i) magnetic field produced around a straight conductor carrying current,

(ii) force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it, and

(iii) current induced in a coil due to its rotation in a magnetic field.

Two circular coils A and B are placed closed to each other. If the current in coil A is changed, will some current be induced in the coil B? Give a reason