Engineering Physics

Multiple Choice Questions

1. Laser action is found in _________ semiconductor.    ( )
   1. direct band gap
   2. indirect band gap
   3. germanium
   4. silicon
2. In computer, printers _________ laser is used.    ( )
   1. He–Ne gas
   2. ruby
   3. semiconductor
   4. CO₂
3. Laser radiation is: ( )
   1. highly monochromatic
   2. partially monochromatic
   3. white light
   4. none
4. Under population inversion, the number of atoms in the higher energy state is _________ than in the lower energy state.    ( )
   1. lesser
   2. larger
   3. both a and b
   4. none
5. Laser radiation is:    ( )
   1. highly directional
   2. monochromatic
   3. coherent and stimulated
   4. all
6. In conventional light sources,    ( )
   1. different atoms emit radiation at different times
   2. there is no phase relation between the emitted photons
   3. different atoms emit photons in different ...