Physics

Grade-9

Easy

Question

# 30 Joules of energy enter a light bulb. 20 joules of energy are transformed into light, how much energy is dissipated as heat?

- 6.7 joules
- 10 joules
- 13 joules
- 100 joules

Hint:

- energy input = useful energy output + waste energy

## The correct answer is: 10 joules

- energy input = useful energy output + waste energy
- Waste or heat energy=Input-Output=30-20=10J

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