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Describe the V-I characteristics of a photodiode.

Important Questions on Semiconductor Electronics: Materials, Devices and Simple Circuits

MEDIUM
How will you obtain AND, OR and NOR gates by using NAND and NOT gates? Write symbols, Boolean formula and truth table.
EASY

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R

Assertion A: Photodiodes are used in forward bias usually for measuring the light intensity.

Reason R: For a p-n junction diode, at applied voltage V the current in the forward bias is more than the current in the reverse bias for Vz>±VV0 where V0 is the threshold voltage and Vz is the breakdown voltage.

In the light of the above statements, choose the correct answer from the options given below

MEDIUM
The photodiode is used to detect the optical signals. These diodes are preferably operated in reverse biased mode because
EASY
What are the basic conditions of biasing the emitter-base and collector-base junctions of a transistor for its proper functioning?
MEDIUM

Three photo diodes D1, D2 and D3 are made of semiconductors having band gaps of 2.5eV, 2eV and 3eV, respectively. Which ones will be able to detect light of wavelength 600 nm ?

Given Planck constant is h=6.62×10-34 m2 kg s-1,speed of light c=3×108 ms-1

MEDIUM
With the circuit diagram, distinguish between LED and photodiode. What is dark current?
MEDIUM

Match the following List-I with List-II

  List I   List II
A Transistor amplifier I Active region
B Transistor switch II Cut-off region
C Zener diode III Voltage regulator
D Fermi level IV Average energy of charge carriers

The correct answer is:

EASY
Give two points of difference between n-type and p- type semiconductor.
MEDIUM

The value of the resistor, RS, needed in the DC voltage regulator circuit shown here, equals:

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EASY
A Zener diode with a breakdown voltage of 4 V is connected in series with a resistance R to a battery of emf 10 V. The maximum power dissipation rating for the Zener diode is 1 W. The value of R to ensure maximum power dissipation across the diode is
MEDIUM
Discuss the working of a photodiode. Why a photodiode is operated in reverse bias mode?
MEDIUM
Three photodiodes D1,D2 and D3 are made of semiconductors having band gaps of 2.5eV, 2eV and 3eV respectively. Which one will be able to detect light of wavelength λ=6000 Å?
EASY

Two p - n photodiodes are fabricated from semiconductors with band gap of 2.8eV and 2.6eV, respectively.

Choose the correct statement from the following.