On what principle does an electric heater work?

Electric Heater works on Joule's law of heating.

When an electric current flows through a resistor, it heats up, the energy converted as heat is proportional to the square of the value of the current and the value of the barrier. That is, there should be such a wire, whose resistance is very high and it does not burn even when it is hot.

Room Heater

Electricity is a power. Just as a stream of water flows, so does electric power. But it has some rules.

 1. It flows / flows through metal and matter. Some metals strongly oppose its flow. Some metals do not resist at all.

2. Metals which resist electric current are used in heaters. When a metal opposes the flow of electricity, heat is generated because of the opposition.

3. For the heater, a metal wire is used to resist the flow of electricity. As electric current is released in the wire - the wire heats up.

Spring Element Heater

4. The construction of the heater

The anti-current wire is kept in a tube.  The wire should not have direct contact with the tube. For this, the wire is wrapped in insulation and then filled in the tube. Due to Insulation, the flow of electricity does not reach the outer tube.

5. Both the mouths of the tube are tightly closed so that water does not enter. Insulation - Electricity does not flow through it at all, such as glass, rubber, dry wood etc. But the tubes get hot.

6. There is a direct contact between this tube and water. Due to the flow of electricity, the anti-flow wire heats up.  Due to this heat, the outer tubes also get hot. The water also gets heated due to the tube being in direct contact with the water.

Water Heater

 7. It has a controller. These controllers keep on measuring the temperature of the water. The controller shuts off the flow of electricity when the water is heated to some degree. Due to this the water does not get too hot.