When a charge moves in a conductor it does work, which results in heating the conductor. Thus electric energy in the form of electric current is converted into heat energy. If the resistance of a wire is R ohms and the current flowing through it is l amperes, the heat produced per second in the wire is lR joules.
The heating effect of electric current is made use of in a variety of appliances, such as a geyser, iron, toaster, oven, room heater, and so on. These appliances have coils of nichrome (an alloy of nickel and chromium), which are heated when current is passed. Whenever electricity is used for heating water or other liquids, the heating element is well insulated and enclosed in a tube. Otherwise the liquids will become live and therefore dangerous. In an electric iron, the heating element is sandwiched between two thin sheets of mica, which is highly insulating and can withstand high temperature.
The heating effect of electric current is made use of in a variety of appliances, such as a geyser, iron, toaster, oven, room heater, and so on. These appliances have coils of nichrome (an alloy of nickel and chromium), which are heated when current is passed. Whenever electricity is used for heating water or other liquids, the heating element is well insulated and enclosed in a tube. Otherwise the liquids will become live and therefore dangerous. In an electric iron, the heating element is sandwiched between two thin sheets of mica, which is highly insulating and can withstand high temperature.