Tag: optoelectronic devices

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Questions Related to optoelectronic devices

Multiple choice physics optoelectronic devices resistance and temperature

A solid reflects incident light and its electrical conductivity decreases with temperature. The bonding in this solid is :

  1. ionic

  2. covalent

  3. metallic

  4. molecular
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Metals reflect incident light by the vibrations of free electrons under the influence of electric field of incident wave. The conductivity of metals decreases with increase of temperature due to increase in random motion of free electrons. The bonding is therefore metallic.

Multiple choice physics optoelectronic devices resistance and temperature

LEDs are better than conventional incandescent power lamps because:

  1. LEDs have higher efficiency.

  2. LEDs look beautiful.

  3. LEDs are cheap.

  4. all of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

LEDs are better than conventional incandescent power lamps because:-

i)LEDs use less power (watts) per unit of light generated (lumens)
ii) LEDs have higher effiiciency.
iii)LEDs have longer lifetime.
iv)LEDs are cheap.
v)LEDs look beautiful.
Hence option D is correct.

Multiple choice physics optoelectronic devices resistance and temperature

A laser device produces amplification in the

  1. Microwave region

  2. Ultraviolet or visible region

  3. Infrared region

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A laser device produces amplification in the Ultraviolet or visible region of the spectrum. 

Multiple choice physics optoelectronic devices resistance and temperature

LASER is an acronym for light amplification by.

  1. Stimulated energetic radiation

  2. Spontaneous emission of radiation

  3. Stimulated emission of radiation

  4. Spontaneous emission of radio waves
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation".