1- Which of the following are smallest known Lasers?
(A) Diode Laser
(B) Argon Laser
(C) Excimer Laser
(D) Helium-Neon Laser
Ans:- (A) Diode Laser
2- _______ Laser has extensive industrial use.
(A) Solid Laser
(B) He-Ne Laser
(C) Nd:YAG Laser
(D) Crypton Laser
Ans:- (C) Nd:YAG Laser
3- The light from a laser source is monochromatic because all the photons
(A) are in Phase
(B) have same Energy
(C) Are in the same Direction
(D) have same Amplitude
Ans:- (B) have same Energy
4- Principle of laser is
(A) Spontaneous absorption
(B) Simulated emission
(C) Induced emission
(D) both (B) and (C)
Ans:- (D) both (B) and (C)
5- Laser beam is made a of
(A) Electrons
(B) Highly coherent photons
(C) Elastic particles
(D) Excited atoms
Ans:- (B) Highly coherent photons
6- Two light-sources are said to be coherent if
(A) they vibrate in same Phase
(B) they vibrate with constant Phase difference
(C) (A) or (B)
(D) (A) and (B)
Ans:- (C) (A) or (B)
7- A hologram records _______of light
(A) Intensity
(B) Frequency
(C) Intensity and Phase
(D) Frequency and Phase
Ans:- (C) Intensity and Phase
8- Radiations emitted by radioactive substances is
(A) Alpha
(B) Beta
(C) Gamma
(D) All of the above
Ans:- (D) All of the above
9- The combination of protons and neutrons in a nucleus is called
(A) Nucleolus
(B) Nucleons
(C) Nuclides
(D) Neutrinos
Ans:- (B) Nucleons
10- Radioactive emissions that are more harmful to human body is
(A) Alpha particles
(B) Beta particles
(C) Gamma radiations
(D) Neutrons
Ans:- (C) Gamma radiations
11- Half-life in a radioactive decay is
(A) The time required for the material to decay completely
(B) The time required for the material to decay to half its original volume
(C) The time required for the material to decay to half its original mass
(D) Half time required for the material to decay completely
Ans:- (C) The time required for the material to decay to half its original mass
12- Wave number is directly related to
(A) Wavelength
(B) Energy
(C) Frequency
(D) Intensity
Ans:- (C) Frequency