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Working of an Electric Bulb Video Lecture | Science Class 7

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FAQs on Working of an Electric Bulb Video Lecture - Science Class 7

1. How does an electric bulb work?
Ans. An electric bulb works by passing an electric current through a filament, which is usually made of tungsten. As the current flows through the filament, it heats up and emits light. This process is called incandescence.
2. What is the purpose of the filament in an electric bulb?
Ans. The filament in an electric bulb serves as the source of light. When an electric current passes through the filament, it heats up and emits light due to its high temperature. The filament is made of tungsten because it has a high melting point and can withstand the heat produced.
3. Can an electric bulb work without electricity?
Ans. No, an electric bulb cannot work without electricity. It requires an electric current to pass through the filament and generate light. Without electricity, there is no source of energy to heat up the filament and produce light.
4. What happens when an electric bulb burns out?
Ans. When an electric bulb burns out, it means that the filament inside the bulb has broken or worn out. As a result, the circuit is broken, and no current can flow through the filament. This leads to the bulb not emitting any light.
5. How long does an electric bulb typically last?
Ans. The lifespan of an electric bulb can vary depending on factors such as its quality, usage, and wattage. Generally, incandescent bulbs last for around 1,000 to 2,000 hours, while LED bulbs can last for up to 25,000 hours or more. However, individual bulbs may have different lifespans based on their specific specifications and usage patterns.
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