Explain the construction and working of a photocell. State its any two applications.

Explain the construction and working of a photocell. State its any two applications.
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1 Answer

Answer :

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Construction: 1. It consists of evacuated glass bulb having cathode (K) and anode (A). 2. The semi cylindrical cathode coated with photosensitive material from inner side. 3. The anode is platinum rod. 4. The cathode is connected to negative terminal of battery and anode is connected to positive terminal of battery.


Working: Photoelectric cell is a device which converts light energy into electrical energy. When light of a suitable frequency is allowed to fall on cathode, it emits Photoelectrons. These photoelectrons are attracted by anode. The photoelectric current flows through the circuit & millimeter Shows the deflection.


Applications:-

1) It is used for automatic control of traffic signals.

2) It is used to switch on and off automatically the street light.

3) It is used in Burglar alarm.

4) It is used in TV set.

5) It is used in fire alarms.

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