MCQ On Class 12 Physics Chapter 11 Dual Nature of Radiation and Matter

1 According to Einstein’s photoelectric equation, the graph of kinetic energy of the photoelectron emitted from the metal versus the frequency of the incident radiation gives a straight line graph, whose slope

A depends on the intensity of the incident radi-ation.

B depends on the nature of the metal and also on the intensity of incident radiation.

C is same for all metals and independent of the intensity of the incident radiation.

D depends on the nature of the metal.

View Answer

Answer:is same for all metals and independent of the intensity of the incident radiation.

2 In photoelectric effect, the photoelectric current is independent of

A intensity of incident light

B potential difference applied between the two electrodes

C the nature of emitter material

D frequency of incident light

View Answer

Answer:frequency of incident light

3 Which of the following statements is correct regarding the photoelectric experiment?

A The photocurrent increases with intensity of light.

B Stopping potential increases with increase in intensity of incident light.

C The photocurrent increases with increase in frequency.

D All of these

View Answer

Answer:The photocurrent increases with intensity of light.

4 In photoelectric effect, stopping potential depends on

A frequency of incident light

B nature of the emitter material

C intensity of incident light

D both (a) and (b)

View Answer

Answer:both (a) and (b)

5 A metal surface ejects electrons when hit by green light but nothing when hit by yellow light. The electrons will be ejected when the surface is hit by

A blue light

B heat rays

C infrared light

D red light

View Answer

Answer:blue light

6 The maximum value of photoelectric current is called

A base current

B saturation current

C collector current

D emitter current

View Answer

Answer:saturation current

7 The phenomenon of photoelectric emission was discovered in 1887 by

A Albert Einstein

B Heinrich Hertz

C Wilhelm Hallwachs

D Philipp Lenard

View Answer

Answer:Heinrich Hertz

8 In photoelectric effect, the photocurrent

A depends both on intensity and frequency of the incident light.

B does not depend on the frequency of incident light but depends on the intensity of the inci-dent light.

C decreases with increase in frequency of inci-dent light.

D increases with increase in frequency of inci-dent light.

View Answer

Answer:does not depend on the frequency of incident light but depends on the intensity of the inci-dent light.

9 Which phenomenon best supports the theory that matter has a wave nature?

A Electron momentum

B Electron diffraction

C Photon momentum

D Photon diffraction

View Answer

Answer:Electron diffraction

10 The minimum energy required for the electron emission from the metal surface can be supplied to the free electrons by which of the following physical processes?

A Thermionic emission

B Field emission

C Photoelectric emission

D All of these

View Answer

Answer:All of these

11 Cathode rays were discovered by

A Maxwell Clerk James

B Heinrich Hertz

C William Crookes

D J.J. Thomson

View Answer

Answer:William Crookes

12 The figure shows stopping V0A potential V0 and frequency o for two different metallic surfaces A and B. The work function of A, as compared to that of B is

Class 12 Physics Chapter 11 Dual Nature of Radiation and Matter

A less

B more

C equal

D nothing can be said

View Answer

Answer:less

13 Who established that electric charge is quantised?

A J.J. Thomson

B William Crookes

C R.A. Millikan

D Wilhelm Rontgen

View Answer

Answer:R.A. Millikan

14 What is the de-Broglie wavelength of an electron accelerated from rest through a potential difference of 100 volts?

A 12.3 Å

B 1.23 Å

C 0.123 Å

D None of these

View Answer

Answer:1.23 Å

15 Compared to liquids and solids, gases are:

A good conductors of electricity

B best conductors of electricity

C very poor conductors of electricity

D good or bad conductors of electricity depending upon the nature of the gas

View Answer

Answer:very poor conductors of electricity

16 which Characteristic of a target does the Mosley’s law relate the frequency of X-rays?

A density

B atomic number

C atomic weight

D interatomic space

View Answer

Answer:atomic number

17 The de-Broglie wavelength of particle of mass 1 mg moving with a velocity of 1 ms^-1, in terms of Planck’s constant h, is given by (in metre):

A 10⁵h

B 10⁶ h

C 10^-3 h

D 10³ h

View Answer

Answer:10⁶ h

18 Which of the following radiations cannot eject photo electrons?

A ultraviolet

B infrared

C visible

D X-rays

View Answer

Answer:infrared

19 When a yellow light is incident on a surface, no electrons are emitted while green light can emit electrons. If the red light is incident on the surface then:

A no electrons are emitted

B photons are emitted

C electrons of higher energy are emitted

D electrons of lower energy are emitted

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