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A light emitting diode produces light when it is:

A light emitting diode produces light when it is: Correct Answer Forward biased

Light-emitting diodes (LED’s) are specially doped P N junction diodes, which emit light when a proper forward bias is applied across the diodes.

The LED’s fabricated by Gallium Phosphide produces visible red light and Gallium Arsenide Phosphide semiconductor produces visible red light.

Infrared LED’s are designed by Gallium Arsenide semiconductors which emit invisible infrared light in forward bias.

Related Questions

Assertion (A): A p-n junction diode with low junction depth can be used as a solar cell when illuminated by suitable light (wavelength) at the top thin layer above the junction. Reason (R): A p-n junction diode under no condition can be used as a solar cell. It can be used only as a light-emitting diode for optoelectronic applications.
Assertion (A): Light Emitting Diode (LED) lamps offer longer service life as compared to Compact Fluorescent Lamps (CFL).
Reason (R): Light Emitting Diodes (LED) lamps are more energy efficient as compared to the Compact Fluorescent Lamps (CFL).
Select the correct answer:
Read the following passage carefully and choose the most appropriate answer to the question out of the four alternatives.
The human eye is a complex part of the body that is used for seeing. Eyes enable people to perform daily tasks and to learn about the world that surrounds them. Sight, or vision, is a rapidly occurring process that involves continuous interaction between the eye, the nervous system, and the brain. When someone looks at an object, what he really sees is the light reflected from the object. This reflected light passes through the lens and falls on the retina of the eye. Here the light induces nerve impulses that travel through the optic nerve to the brain and then over other nerves to muscles and glands.
The eye is similar to a television camera. Both the eye and the television camera convert light energy to electrical energy. The eye converts light to nerve impulses that are interpreted by the brain as the sense perception called sight. A television camera converts light to electronic signals that are broadcast and transformed into light images in a television receiver. It is wonderful that human eyes blink an average of once every six seconds. This washes the eye with the salty secretion from the tear or lachrymal glands. Each tear gland is about the size and shape of an almond. These glands are situated behind the upper eyelid at the outer corner of the eye. After passing over the eye, the liquid from the gland is drained into the nose through the tear duct at the inner corner of the eye. The sense perception that the brain releases after the eye converts light to nerve impulses is known as
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