What is a solenoid?

For the circular coil carrying current shown alongside,draw magnetic field lines. Decide which of its face behaves as North Pole and which face as South Pole. Give reason to justify your answer.

On which principle is electricity generated in a power plant?

If the direction of current is reversed,the direction of magnetic field is also reversed.

Suggest one way of discriminating a wire carrying current from a wire carrying no current.

What does the direction of the thumb indicate in the right-hand thumb rule?