Question

What does LED stand for?
A. Light emitting display
B. Light energy display
C. Light emitting diode
D. Light emitting detector

Answer 1

Hint: LEDs are electronic devices which are basically diodes. They are extensively used in almost every other electronic gadget these days, mainly for display purposes because they are capable of emitting light of various colours.

Complete Step-by-Step solution:
A LED is an electronic device made of semiconductors. It emits light of different wavelengths or colours depending on the type of semiconductor when electric current is passed through it.
A diode is made by joining a p-type semiconductor with n-type semiconductor. Electrons are majority charge carriers in n-type semiconductors and holes are majority charge carriers in p-type semiconductors. When electric current is applied to the diode, these charge carriers combine with each other producing energy in the form of photons or light. Now the wavelength of the photons emitted depends on the type of material used in the semiconductor. There are certain semiconductors like gallium arsenide (GaAs), gallium arsenide phosphide (GaAsP), etc. emit light in the visible region of the spectrum.
Diodes, especially LEDs, have proved to be a great invention. Since LEDs can emit visible light, they can be used for display purposes like in television screens which has led to the invention of LED televisions.
Since LEDs emit light and are made of diodes, they stand for Light Emitting Diodes.
Therefore, the correct answer to our question is option C.

Note: The LEDs are used for display but it is only one of their several applications, therefore, students must not make the mistake of choosing option A or B. Also, detection is not one of the applications of diodes; hence, option D is also wrong. These facts must be kept in mind while solving this question.