Principle involved in the glowing of an electric bulb: Heating effect of current

The principle involved in the glowing of an electric bulb is the heating effect of current. When an electric current passes through a filament inside the bulb, it heats up and produces light.

Explanation:
The heating effect of current is a phenomenon where electrical energy is converted into heat energy when an electric current flows through a conductor. This effect occurs due to the resistance offered by the conductor to the flow of electrons. In the case of an electric bulb, the filament acts as the conductor.

Working of an electric bulb:
1. The electric bulb consists of a glass bulb with a filament made of tungsten wire inside it. The filament is connected to the base of the bulb through two metal wires.
2. When the bulb is connected to a power source, an electric current flows through the filament.
3. The filament has a high resistance, which causes it to heat up.
4. As the temperature of the filament increases, it starts to glow and emit light.
5. The filament reaches a high temperature, but it does not burn because it is placed inside a bulb filled with inert gases like argon or nitrogen. These gases prevent the filament from oxidizing and burning out quickly.
6. The emitted light from the filament illuminates the surroundings, providing us with light.

Reason behind the heating effect:
The heating effect of current is a result of collisions between the free electrons and atoms or ions in the conductor. As the electrons move through the filament, they collide with atoms, transferring their kinetic energy to them. This energy is absorbed by the atoms, causing them to vibrate more vigorously, and thus increasing the temperature of the filament.

Advantages of using the heating effect of current in electric bulbs:
1. The heating effect of current allows electric bulbs to produce light efficiently.
2. The filament can reach high temperatures, allowing it to emit bright light.
3. The process is relatively simple and cost-effective, making electric bulbs widely available and affordable.

In conclusion, the glowing of an electric bulb is based on the heating effect of current. The electric current passing through the filament heats it up, causing it to emit light and illuminate the surroundings.