Question

Q1)what are the factors on which the amount of heat produced in the in a conductor depend on? Q2)what happens to the compass needle kept near a current carrying wire? Explain.

Answer 1

1-Amount of heat is proportional to the square of the current flowing in the wire.Joule heating law.
2-The compass needle has it's own magnetic feild.A freely suspended magnet rests in north South direction.It can only deflect when there is an influence of another force.Thus when the compass needle is kept near a current carrying conductor,it deflects under the influence of electric feld of the wire.