**Heating Effect of Electric Current**

The correct answer is option 'C' - Heating effect.

The heating effect of electric current refers to the phenomenon where electric current flowing through a conductor produces heat. This effect is used in various electrical appliances including electric lamps.

**Explanation:**

When an electric current passes through a conductor, such as the filament in an electric lamp, it encounters resistance. This resistance causes the flow of electrons to slow down and collide with the atoms of the conductor. These collisions result in the conversion of electrical energy into heat energy.

**How the heating effect makes an electric lamp glow:**

1. The filament inside an electric lamp is made of a material that has high resistance to the flow of electric current, such as tungsten.

2. When an electric current is passed through the filament, it experiences resistance, causing the filament to heat up.

3. As the temperature of the filament increases, it starts to emit light. This phenomenon is known as incandescence.

4. The filament inside the lamp glows and produces visible light due to the heating effect of the electric current.

5. The intensity of the light emitted by the lamp depends on the amount of current flowing through the filament and the temperature reached by the filament.

**Other examples of the heating effect:**

The heating effect of electric current is not only observed in electric lamps but also in various electrical appliances and devices. Some examples include:

- Electric heaters: Electric heaters use the heating effect to convert electrical energy into heat energy, providing warmth in homes and buildings.

- Electric stoves: Electric stoves use the heating effect to generate heat for cooking by passing electric current through heating elements.

- Electric irons: Electric irons utilize the heating effect to heat up the metal plate, allowing for the smoothing of clothes.

- Electric kettles: Electric kettles use the heating effect to boil water by passing electric current through a heating element.

In conclusion, the electric lamp glows due to the heating effect of the electric current passing through its filament. The resistance encountered by the current in the filament causes it to heat up and emit visible light, resulting in the glow of the lamp.

Option c is the answer because electric lamp glows due to heat so that answer is Heating effect