In obtaining an X-ray photograph of our hand we use the principle of______________?

A. Photo electric effect
B. Ionization
C. Shadow photograph
D. Any of above

When we excite some atoms by heat collision or electrical discharge they will________________?

A. Radiate electromagnetic energy with a continuous distribution of wavelength
B. Absorb particular wavelengths when white light is incident on them
C. Radiate electromagnetic energy of discrete characteristic wavelength
D. Emit either invisible or visible light

Which one of following postulate is in accordance with the Rutherfords model ?

A. Continuous spectra for atoms
B. Discrete spectra for atoms
C. Either continuous nor discrete
D. No spectrum

Ground state energy of the 4th orbit in a H-atom is_____________?

A. 13.60 ev
B. 3.40 ev
C. 0.85 ev
D. 1.51 ev

The electric P.E of an electron in an orbit at a distance rn from the positive charge_____________?

A. Ke2/rn
B. Ke2/rn2
C. Àke2/rn
D. Àke2/rn2

Bracket series is obtained when all transition of electron terminate on_______________?

A. 4th orbit
B. 5th orbit
C. 3rd orbit
D. 2nd orbit

The penetrating power of X-rays depends on their______________?

A. Applied voltage
B. Frequency
C. Source
D. All of the above

Reverse process of photoelectric effect is_______________?

A. Pair production
B. Compton effect
C. Annihilation of matter
D. X-rays production

Radiation with wavelength longer than red lights______________?

A. Ultraviolet rays
B. X-rays
C. Infra red radiation
D. Visible radiation

In an electronic transition atom cannot emit______________?

A. Γ-rays
B. Infra red radiation
C. Visible light
D. Ultraviolet rays