CBSE
Multiple Choice QuestionsColour of star depends upon
luminosity
temperature
brightness
all of these
If red light is replaced by white light then width of diffraction pattern will
increases
decreases
a central white band is obtained
no effect
The de-Broglie wavelength of an electron having 80 eV of energy is nearly (1 eV = 1.6 × 10-19J, mass of electron = 9.1 × 10-31 kg, Planck's constant = 6.6 × 10-34 J-s)
140 Å
0.14 Å
14 Å
1.4 Å
Assertion: On increasing the frequency of light larger number of photoelectrons are emitted.
Reason: The number of electrons emitted depends on the intensity of incident light.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reasonn are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If assertion is false but reason is true.
Maximum velocity of photoelectron emitted is 4.8m/s. If e/m ratio of the electron is then stopping potential is given by
5 10-10 J/C
3 10-7 J/C
7 10-11 J/C
2.5 10-2 J/C
In Planck's oscillator energy is given as
E = If K = 0, then energy would be
hν
0
Kt
∞
Which of the following figures represents the variation of the particle momentum and associated de-Broglie wavelength?
Maximum velocity of the photoelectrons emitted by a metal surface is 1.2x106 ms-1. Assuming the specific charge of the electron to be 1.8 x1011 C kg-1, the value of the stopping potential in volt will be
2
3
4
6
When light of wavelength 300 nm falls on a photoelectric emitter, photoelectrons are liberated. For another emitter, light of wavelength 600 nm is sufficient for liberating photoelectrons. The ratio of the work function of the two emitters is
1 : 2
2 : 1
4: 1
1: 4
The work function of a metal is 3.4 eV. If the frequency of incident radiation is increased to twice, then the work function of the metal becomes
3.4 eV
7.2 eV
6.8 eV
1.7 eV
