According to Ampere's swimming rule, the south pole of the magnetic needle deflects towards _____ hand of the swimmer.

What is the importance of Oersted's experiment?

Describe the magnetic field produced by a solenoid carrying current.

The diagram below shows a magnetic needle kept just below the conductor AB which is kept in the North-South direction.

i) In which direction will the needle deflect when the key is closed?

ii) Why is the deflection produced?

iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB?

iv) Name one device which works on this principle.