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.

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.

ANS 3 Photodiodes are used to detect optical signals of different
intensities by changing current flowing through them.

Applications of photodiodes:
1. In detection of optical signals.
2. In demodulation of optical signals.
3. In light operated switches.
4. In speed reading of computer punched cards.
5. In electronic counters