The magnetic field produced by a straight current-carrying conductor is in the form of concentric circles.

Define magnetic field. $A$ compass needle gets deflected when brought near a bar magnet. Why? List three properties of magnetic field lines.

What are permanent magnets and electromagnets? Give two uses of each.

The flow of a current in a circular loop of a wire creates a magnetic field at its centre. How can the existence of this field be detected? State the rule which helps to predict the direction of this magnetic field.

Which type of current is obtained from a battery?

Name three colours used and names of the wires used in household wiring.