EASY
Earn 100

Order of pressure inside a photo cell is :-

50% studentsanswered this correctly

Important Questions on Semiconductor Devices

EASY
What is the principle of a photo-diode ?
EASY

Name the optoelectronic device which convert optical radiation into electricity.

EASY

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

Assertion A: Photodiodes are preferably operated in reverse bias condition for light intensity measurement.
Reason R: The current in the forward bias is more than the current in the reverse bias for a p-n junction diode.


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

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
The photodiode is used to detect the optical signals. These diodes are preferably operated in reverse biased mode because
EASY

Name the optoelectronic device used to detect optical signal

MEDIUM

Ge and Si diodes start conducting at 0.3 V and 0.7 V respectively. In the following figure if Ge diode connection are reversed, the value of V0 changes by: (assume that the Ge diode has large breakdown voltage)

Question Image

MEDIUM
With the circuit diagram, distinguish between LED and photodiode. What is dark current?
MEDIUM
Discuss the working of a photodiode. Why a photodiode is operated in reverse bias mode?
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
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?
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
With increasing biasing voltage of a photo diode, the photocurrent magnitude:
EASY
Consider the junction diode as ideal. The value of current flowing through AB is:
Question Image
EASY
In an unbiased p - n junction electrons diffuse from n-region to p-region because:
EASY
The I - V characteristics of an LED is:
EASY
Why photo diodes are required to operate in reverse bias? Explain.
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.