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Question
Name the device which converts the change in intensity of illumination to change in electric current flowing through it. Plot I-V characteristics of this device for different intensities. State any two applications of this device.
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Solution
Photodiodes are used to detect optical signals of different intensities by changing current flowing through them.
I-V Characteristics of a photodiode
Applications of photodiodes:
- In detection of optical signals.
- In demodulation of optical signals.
- In light operated switches.
- In speed reading of computer punched cards.
- In electronic counters.
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