Fill in the blanks:
When current is switched on in a room heater, it …………………….

Hint: Due to the heating effect of current it produces heat as the switch is on in the room heater. The current can produce such a heating effect. While current is passing through a conductor, heat is produced. This is the heating effect of a conductor. Here an energy conversion is taking place. That is, the electrical energy is here then converted into heat energy.

Complete step by step answer:
Here one form of energy is converted into another form of energy. That is, the electrical energy is here then converted into heat energy. The current has an ability to produce heat as it moves through a conductor. This is the heating effect of a conductor. Due to the heating effect of current it produces heat as the switch is on in the room heater. Electric iron and kettle also produce heating effects as in a room heater. This energy conversion takes place at the time when current is passed through a high resistance wire. The resistance wire will become heated because of the production of such a heat energy. It heat is generated due to an opposition in the current flow. Here the opposition is a high resistance.
When current is switched on in a room heater, it produces a heat due to the heating effect of current passing through the conductor.

Note: Fuse can here act as a safety device for the heating effect of electric current. Mostly high resistance wire such as Nichrome is used in an electric heater. Because high resistance can produce more heat energy. Similarly in the case of an electric fan also energy conversion takes place. That is, here the electrical energy is converted into mechanical energy.