Semiconductor Electronics Material Devices and Simple Circuits
151010
Which one of the following statement is not correct in the case of light emitting diodes?
1 It is a heavily doped p-n junction.
2 It emits light only when it is forward biased.
3 It emits light only when it is reverse biased.
4 The energy of the light emitted is less than the energy gap of the semiconductor used.
Explanation:
C Light emitting diodes are specially designed diodes which gives out light radiations when given out light radiations when forward biased. LED's are made of GaAsP, GaP, etc.
J and K CET- 2010
Semiconductor Electronics Material Devices and Simple Circuits
151011
A light emitting diode is:
1 a n-p-n type semiconductor with a forward bias
2 a p-n-p semiconductor with a reverse bias
3 a p-n-p semiconductor with a forward bias
4 a p-n semiconductor with a reverse bias
5 a p-n semiconductor with a forward bias
Explanation:
E A light emitting diode emits spontaneous radiation, under forward bias. In the p-n junction diode doping is heavily. When a junction diode is forward biased, energy is released at the junction due to recombination of electron and holes.
Kerala CEE-2019
Semiconductor Electronics Material Devices and Simple Circuits
151014
The energy of radiation emitted by LED is
1 greater than the band gap of the semiconductor used
2 always less than the band gap of the semiconductor used
3 always equal to the band gap of the semiconductor used
4 equal to or less than the band gap of the semiconductor used
Explanation:
D A light emitting diode converts electrical energy into light energy and it is a semiconductor that emits monochromatic as well as white light. So, the energy of Radiation emitted by LED is equal or less than the band gap of the semi conductor.
Semiconductor Electronics Material Devices and Simple Circuits
151010
Which one of the following statement is not correct in the case of light emitting diodes?
1 It is a heavily doped p-n junction.
2 It emits light only when it is forward biased.
3 It emits light only when it is reverse biased.
4 The energy of the light emitted is less than the energy gap of the semiconductor used.
Explanation:
C Light emitting diodes are specially designed diodes which gives out light radiations when given out light radiations when forward biased. LED's are made of GaAsP, GaP, etc.
J and K CET- 2010
Semiconductor Electronics Material Devices and Simple Circuits
151011
A light emitting diode is:
1 a n-p-n type semiconductor with a forward bias
2 a p-n-p semiconductor with a reverse bias
3 a p-n-p semiconductor with a forward bias
4 a p-n semiconductor with a reverse bias
5 a p-n semiconductor with a forward bias
Explanation:
E A light emitting diode emits spontaneous radiation, under forward bias. In the p-n junction diode doping is heavily. When a junction diode is forward biased, energy is released at the junction due to recombination of electron and holes.
Kerala CEE-2019
Semiconductor Electronics Material Devices and Simple Circuits
151014
The energy of radiation emitted by LED is
1 greater than the band gap of the semiconductor used
2 always less than the band gap of the semiconductor used
3 always equal to the band gap of the semiconductor used
4 equal to or less than the band gap of the semiconductor used
Explanation:
D A light emitting diode converts electrical energy into light energy and it is a semiconductor that emits monochromatic as well as white light. So, the energy of Radiation emitted by LED is equal or less than the band gap of the semi conductor.
Semiconductor Electronics Material Devices and Simple Circuits
151010
Which one of the following statement is not correct in the case of light emitting diodes?
1 It is a heavily doped p-n junction.
2 It emits light only when it is forward biased.
3 It emits light only when it is reverse biased.
4 The energy of the light emitted is less than the energy gap of the semiconductor used.
Explanation:
C Light emitting diodes are specially designed diodes which gives out light radiations when given out light radiations when forward biased. LED's are made of GaAsP, GaP, etc.
J and K CET- 2010
Semiconductor Electronics Material Devices and Simple Circuits
151011
A light emitting diode is:
1 a n-p-n type semiconductor with a forward bias
2 a p-n-p semiconductor with a reverse bias
3 a p-n-p semiconductor with a forward bias
4 a p-n semiconductor with a reverse bias
5 a p-n semiconductor with a forward bias
Explanation:
E A light emitting diode emits spontaneous radiation, under forward bias. In the p-n junction diode doping is heavily. When a junction diode is forward biased, energy is released at the junction due to recombination of electron and holes.
Kerala CEE-2019
Semiconductor Electronics Material Devices and Simple Circuits
151014
The energy of radiation emitted by LED is
1 greater than the band gap of the semiconductor used
2 always less than the band gap of the semiconductor used
3 always equal to the band gap of the semiconductor used
4 equal to or less than the band gap of the semiconductor used
Explanation:
D A light emitting diode converts electrical energy into light energy and it is a semiconductor that emits monochromatic as well as white light. So, the energy of Radiation emitted by LED is equal or less than the band gap of the semi conductor.
