The magnetic field around a current-carrying straight conductor is:

On which principle does an electric generator work?

Explain the phenomenon of electromagnetic induction. Describe an experiment to show that a current is set up in a closed loop when an external magnetic field passing through the loop increases or decreases.

Draw the pattern of magnetic field lines associated with a current-carrying straight conductor. State how the magnetic field produced changes:
$(i)$ with an increase in current in the conductor,and
$(ii)$ with an increase in the distance from the conductor.

How is the magnetic field produced in a solenoid used?

If a circular loop is made of $6$ closely wound turns instead of a single turn,the magnetic field produced at the center of the loop becomes $.........$ times stronger.