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प्रश्न
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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उत्तर
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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संबंधित प्रश्न
If a small voltage is applied to a p-n junction diode, how will the barrier potential be affected when it is(ii) reveres biased?
With what considerations in view, a photodiode is fabricated? State its working with the help of a suitable diagram.
Even though the current in the forward bias is known to be more than in the reverse bias, yet the photodiode works in reverse bias. What is the reason?
Using the necessary circuit diagrams, show how the V-I characteristics of a p-n junction are obtained in
Forward biasing
How are these characteristics made use of in rectification?
Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy band gap respectively equal to (Eg)C, (Eg)Si and (Eg)Ge. Which of the following statements is true?
Write briefly the important processes that occur during the formation of p−n junction. With the help of necessary diagrams, explain the term 'barrier potential'.
Briefly explain its working. Draw its V - I characteristics for two different intensities of illumination ?
Write the important considerations which are to be taken into account while fabricating a p-n junction diode to be used as a Light Emitting Diode (LED). What should be the order of band gap of an LED, if it is required to emit light in the visible range? Draw a circuit diagram and explain its action.
Draw solar cell V-I characteristics.
A p-n photodiode is fabricated from a semiconductor with a band gap of 2.5 eV. lt can detect a signal of wavelength ______.
How can a photodiode be used to measure light intensity?
