In which of the following devices is an electric motor $NOT$ used?

$A$ device used for producing current is:

What is meant by electromagnetic induction? State the rule which helps in determining the direction of induced current.

$A$ current-carrying wire produces:

Explain the meanings of the words "electromagnetic" and "induction" in the term electromagnetic induction. List three factors on which the value of induced current produced in a circuit depends. Name and state the rule used to determine the direction of induced current. State one practical application of this phenomenon in everyday life.

The essential difference between an $AC$ generator and a $DC$ generator is that