Wave-like characteristic of electron is demonstrated by______________?

A. Line spectrum of atoms
B. Production of x-rays.
C. Diffraction by crystalline solids
D. Photoelectric effect

Electron cannot exist in the nucleus it is confirmed by observing that______________?

A. It does emit radiation
B. Its size as compare to proton and neutron is very small
C. No antiparticle of electron is present
D. The velocity of electron must be very high according to uncertainty principle

In normal state of energy the incident high energy photons will be______________?

A. Stimulated
B. Absorbed
C. Cause x-ray emission
D. Cause laser production

In laser production the state in which more atoms are in the upper state than in the lower one is called_____________?

A. Metal stable state
B. Normal state
C. Inverted population
D. All the above

The metastable state for an atom in laser light is_____________?

A. 10-4 sec
B. 10-5 sec
C. 10-3 sec
D. 10-8 sec

In He-Ne laser the lasing action is produced by_______________?

A. Ne only
B. He-ne both
C. Electrons of he
D. Electrons ne

Reflecting mirrors in laser is used to______________?

A. Further stimulation
B. Lasing more
C. For producing more energetic lasers
D. All

The velocity of laser light is___________________?

A. Less than ordinary light
B. More than ordinary light
C. Equal to ordinary light
D. Different for different colours or frequency

Electrons present in p-type material due to thermal pair generation are_____________?

A. Majority carriers
B. Minority carriers
C. Dual carriers
D. Blockers

Semi-conductor germanium and silicon are_________________?

A. Pentavalent
B. Trivalent
C. Divalent
D. Tetravalent