Dual Nature of Radiation and Matter  MCQs

MCQs of Dual Nature of Radiation and Matter

Showing 71 to 80 out of 186 Questions
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71.
The photoelectric threshold wavelength for potassium having work function of 2 eV, is _____ . (Take h=6.6×10-34 Js , 1eV=1.6×10-19 J , c=3×108 ms-1 )
(a) 1240 nm
(b) 310.7 nm
(c) 1860 nm
(d) 618.7 nm
Answer:

Option (d)

72.
A photon of energy 8 eV is incident on a metal surface of threshold frequency 1.6×1015 Hz. The maximum kinetic energy of photo electrons emitted is _____ .
(a) 4.2 eV
(b) 2.8 eV
(c) 1.4 eV
(d) 0.8 eV
Answer:

Option (c)

73.
Ultraviolet light of wavelength 200 nm is incident on a polished surface of Fe ( Iron). Work function of the surface is 4.71 eV. What will be its stopping potential ? ( Take h=6.6×10-34 Js , 1eV=1.6×10-19 J , c=3×108 ms-1 )
(a) 1.5 V
(b) 2.5 V
(c) 0.5 V
(d) None of the above
Answer:

Option (a)

74.
The number of photons of wavelength 660 nm emitted per second by an electric bulb of 60 W is _____ . ( Take h=6.6×10-34 Js )
(a) 2×10-20
(b) 2×1020
(c) 3×1020
(d) 1.5×1020
Answer:

Option (b)

75.
A α-particle and a deuteron are moving with velocity v and 2v respectively. What will be the ratio of their de Broglie wave length ?
(a) 1:2
(b) 2:1
(c) 1:1
(d) 2:1
Answer:

Option (c)

76.
In photoelectric, the threshold wavelength of sodium is 5000 Å . Find its work function. [h=6.6×10-34 Js , 1eV=1.6×10-19 J , c=3×108 ms-1 ]
(a) 10 eV
(b) 7.5 eV
(c) 5.0 eV
(d) 2.5 eV
Answer:

Option (d)

77.
The sun delivers 103 Wm-2 of electromagnetic flux on the Earth's surface. The total power that is incident on a roof of dimension 6 m × 30 m is _____ .
(a) 0.9×105 W
(b) 1.8×105 W
(c) 4.5×105 W
(d) 7.2×105 W
Answer:

Option (b)

78.
If the linear momentum of a particle is 2.2×104 kg ms-1 , then what will be its de Broglie wavelength ?
(a) 6×10-29 m
(b) 3×10-29 m
(c) 6×10-29 nm
(d) 3×10-29 nm
Answer:

Option (d)

79.
The photoelectric effect represents that _____ .
(a) light has a particle nature
(b) electron has a wave nature
(c) proton has wave nature
(d) None of the above
Answer:

Option (a)

80.
The frequency of a photon having energy 100 eV is _____ Hz. ( Take h=6.6×10-34 Js , 1eV=1.6×10-19 J )
(a) 2.417×10-16
(b) 2.417×1016
(c) 2.417×1017
(d) 10.54×1017
Answer:

Option (b)

Showing 71 to 80 out of 186 Questions
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