According to the NEW colour convention which colour of wire is connected to :

(a) the metal body of the appliance

(b) the switch of the appliance?

(a) Which of the two, alternating current or direct current, produces a varying magnetic field when it flows through a conductor?

(b) State the frequency of the alternating current supply in India

Copper wire is wound around a steel bar FT. Current is allowed to pass through the coil for some time and then the bar is removed.

(a) Draw only the magnetised bar FT and mark its poles.

(b) Trace two magnetic lines of force around FT clearly indicating the direction.

A current flows through a metallic conductor for a long period of time. State the change you would expect in its:

(a) Resistance

(b) Resistivity