Class 12 Dual Nature Of Radiation And Matter CBSE Questions & Answers

Class 12 · Dual Nature Of Radiation And Matter

This is Physics Class 12 Dual Nature Of Radiation and Matter CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
work function of a metal is the
  • A
    maximum energy required by an electron to escape from the metal surface
  • B
    energy required by an electron to get absorbed in the metal surface
  • C
    minimum energy required by an electron to escape from the metal surface
    Correct
  • D
    energy required by an electron to escape from the metal surface
2
In which case is electron emission from a metal not known?
  • A
    Applying a very strong magnetic field to a metal
    Correct
  • B
    Illuminating a metal surface with suitable light
  • C
    Applying a very strong electric field to a metal
  • D
    Heating the metal sufficiently
3
Photoelectric effect is
  • A
    emission of electrons by metals when heated
  • B
    emission of electrons by metals when illuminated by light of suitable frequency
    Correct
  • C
    emission of electrons by glass when illuminated by light of suitable frequency
  • D
    emission of electrons by insulators when illuminated by light of suitable frequency
4
Photoelectric effect is possible
  • A
    with only white light
  • B
    with both visible and uv depending on the metal
    Correct
  • C
    with only ultraviolet
  • D
    with only visible
5
In Photoelectric effect
  • A
    electrical energy is converted magnetic field energy
  • B
    light is converted into electrical energy
    Correct
  • C
    electrical energy is converted into light energy
  • D
    electrical energy is converted into heat
6
In the above experimental set up for studying photoelectric effect, if keeping the frequency of the incident radiation and the accelerating potential fixed, the intensity of light is varied, then
Question 6 figure 1
  • A
    photocurrent decreases nonlinearly with intensity
  • B
    photocurrent remains same with intensity
  • C
    photocurrent decreases linearly with intensity
  • D
    photocurrent increases linearly with intensity
    Correct
7
Stopping potential in the experimental set up shown in figure is
Question 7 figure 1
  • A
    positive potential \({{\rm{V}}_0}\) given to the plate A for which the photocurrent saturates
  • B
    positive potential \({{\rm{V}}_0}\) given to the plate A for which the photocurrent stops or becomes zero
  • C
    positive potential \({{\rm{V}}_0}\) given to the plate A for which the photocurrent stops increasing
  • D
    negative potential \({{\rm{V}}_0}\)given to the plate A for which the photocurrent stops or becomes zero
    Correct
8
For a given frequency of light and a positive plate potential in the set up below, If the intensity of light is increased then
Question 8 figure 1
  • A
    current is unaffected by more intensity
  • B
    current is inversely proportional to intensity
  • C
    current is less with more intensity
  • D
    current is more with more intensity
    Correct
9
In various experiments on photo electricity the stopping potential for a given frequency of the incident radiation
  • A
    is proportional to radiation intensity
  • B
    is independent of the radiation intensity
    Correct
  • C
    is independent of radiation intensity
  • D
    is inversely proportional to radiation intensity
10
In various experiments on photo electricity dealing with the stopping potential dependence on frequency of incident radiation , the conclusion was that stopping potential
  • A
    depends on the initial current
  • B
    depends on the frequency
    Correct
  • C
    depends on the light intensity
  • D
    is independent of frequency
11
According to the Einstein’s model minimum energy needed for the electron to escape from a metal surface having work function \({\phi _0}\), the electron is emitted with maximum kinetic energy \({{\rm{K}}_{{\rm{max}}}}\) =
  • A
    hν - 2 \({\phi _0}\)
  • B
    hν + \({\phi _0}\)
  • C
    hν
  • D
    hν - \({\phi _0}\)
    Correct
12
According to the Einstein’s model the threshold frequency for a metal having work function \({\phi _0}\) is given by
  • A
    \({h \over {{\emptyset _0}}}\)
  • B
    \({\phi _0}\)h
  • C
    \({\phi _0}\)h +100
  • D
    \({{{\emptyset _0}} \over h}\)
    Correct
13
According to the Einstein’s model stopping potential for a metal having work function \({\phi _0}\) is given by
  • A
    \({V_0} = \left( {{h \over e}} \right)\nu - {{{\phi _0}} \over e}\)
    Correct
  • B
    \({V_0} = \left( {{h \over e}} \right)\nu - 2{{{\phi _0}} \over e}\)
  • C
    \({V_0} = \left( {{h \over e}} \right)\nu + {{{\phi _0}} \over e}\)
  • D
    \({V_0} = \left( {{h \over e}} \right)\nu + 2{{{\phi _0}} \over e}\)
14
In interaction of radiation with matter, radiation behaves as if it is made up of particles called
  • A
    bosons
  • B
    positrons
  • C
    electrons
  • D
    photons
    Correct
15
Each photon has the same speed but different
  • A
    frequency
    Correct
  • B
    radius
  • C
    rest mass
  • D
    energy