Q.1
Photons emitted by spontaneous emission are __________
  • a) Coherent and Monochromatic
  • b) Non-coherent and monochromatic
  • c) Coherent and Non-Monochromatic
  • d) Non-Coherent and Non-monochromatic
Q.2
In Stimulated Absorption, what is the lifetime of atoms ground state?
  • a) 1 second
  • b) 1 minute
  • c) 1 hour
  • d) Infinity
Q.3
Phonons are __________
  • a) Quanta of energy
  • b) Quanta of light waves
  • c) Quanta of sound waves
  • d) Quanta of heat
Q.4
The frequency of incident photon so that the atom makes a transition from E1 to E2 should be __________
  • a) E2 – E1
  • b) E2 – E1/c
  • c) E2 – E1/h
  • d) E2 – E1/λ
Q.5
What is the general lifetime of an atom in an exited state?
  • a) 10-10
  • b) 10-8
  • c) 10-6
  • d) 10-4
Q.6
The output of a laser has pulse duration ofms and average output power of 1.W per pulse. How much energy is released per pulse if wavelength isÅ?
  • a) 0.011 J
  • b) 0.024 J
  • c) 0.035 J
  • d) 0.047 J
Q.7
Laser light from a 7mW source of aperture diameter 1.5 cm and wavelengthÅ is focused by a lens of focal lengthcm. The intensity of the image is __________
  • a) 3 X 107 Wm-2
  • b) 4 X 107 Wm-2
  • c) 5 X 107 Wm-2
  • d) 6 X 107 Wm-2
Q.8
For an ordinary light source, the coherence time t = 10-10s. The degree of Monochromaticity for a wavelength ofÅ is ___________
  • a) 0.1 X 10-4
  • b) 0.2 X 10-4
  • c) 0.3 X 10-4
  • d) 0.4 X 10-4
Q.9
In Stimulated emission, the emitted photons are _____________
  • a) Coherent and Monochromatic
  • b) Non-coherent and monochromatic
  • c) Coherent and Non-Monochromatic
  • d) Non-Coherent and Non-monochromatic
Q.10
The following graph is pictorial representation of _____________
Questionengineering-physics-ii-questions-answers10.jpg
  • a) Spontaneous emission
  • b) Spontaneous Absorption
  • c) Stimulated emission
  • d) Stimulated Absorption
0 h : 0 m : 1 s