Dual Nature of Radiation and Matter  MCQs

MCQs of Dual Nature of Radiation and Matter

Showing 91 to 100 out of 186 Questions
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91.
The time taken by a photoelectron to come out after the photon strikes is approximately _____ .
(a) 10-16 s
(b) 10-1 s
(c) 10-4 s
(d) 10-10 s
Answer:

Option (d)

92.
Cathode ray is ______ .
(a) a beam of atoms moving towards cathode
(b) electromagnetic wave
(c) a beam of negatively charged iron moving towards anode
(d) a beam of electrons emitted by cathode
Answer:

Option (d)

93.
A metal surface is illuminated by the photons of energy 5 eV and 2.5 eV respectively. The ratio of their wavelengths is _____ .
(a) 1:3
(b) 1:4
(c) 2:1
(d) 1:2
Answer:

Option (d)

94.
An electron with rest mass m0 moves with a speed of 0.8 C. Its mass when it moves with this speed is _____ .
(a) m0
(b) m06
(c) 5m03
(d) 3m05
Answer:

Option (c)

95.
In fluorescence, there is ______ .
(a) increase in wavelength of emitted radiation
(b) decrease in wavelength of emitted radiation
(c) no change in wavelength of emitted radiation
(d) both increase and decrease in wavelength of emitted radiation
Answer:

Option (a)

96.
Planck's constant has the dimensions of _____ .
(a) energy
(b) mass
(c) frequency
(d) angular momentum
Answer:

Option (d)

97.
A photon of frequency f has a momentum associated with it. If c is the velocity of light, this momentum is _____ .
(a)  hfc2
(b) hfc
(c)  fc
(d) h fc
Answer:

Option (d)

98.
The energy of the visible light is of the order of _____ .
(a) few eV
(b) few KeV
(c) few MeV
(d) 198 eV
Answer:

Option (a)

99.
The energy of a photon of green light of wavelength 5000 Å is _____ ×10-19 J.
(a) 30459
(b) 3.975
(c) 4.132
(d) 8.453
Answer:

Option (b)

100.
If the energy of a photon is 10 eV, then the momentum is _____ .
(a) 5.33×10-23 Ns
(b) 5.33×10-25 kg.ms-1
(c) 5.33×10-29 Ns
(d) 5.33×10-27 kg.ms-1
Answer:

Option (d)

Showing 91 to 100 out of 186 Questions
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