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Types of Lamps

Heating coil ...

Question

Heating coil in fluorescent lamps are coated with thorium oxide to.

A

reflect the electrons

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B

increase electron emission efficiency

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C

decrease electron emission efficiency

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D

absorb the electrons

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Solution

The correct option is B
increase electron emission efficiency

There are two heating coils at the two ends of the tube of the lamp. Due to the flow of electric current, the heating coils become very hot and electrons are emitted. Thorium oxide are coated over the coils to increase the electron emission efficiency.

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