State any two advantages of electromagnets over permanent magnets.

A solid metal weighing 150 g melts at it's melting point of 800 °C by providing heat at the rate of 100 W. The time taken for it to completely melt at the same temperature is 4 min. What is the specific latent heat of fusion of the metal?

Identify the following wires used in a household circuit:

(i) The wire is also called as the phase wire.

(ii) The wire is connected to the top terminal of a three-pin socket.

(i) How can a temperature in degree Celsius be converted into S.I. unit of temperature?

(ii) A liquid X has the maximum specific heat capacity and is used as a coolant in Car radiators. Name the liquid X.