NCERT MCQ CLASS-12 CHAPTER-11 | PHYSICS NCERT MCQ | DUAL NATURE OF RADIATION AND MATTER | EDUGROWN

In This Post we are  providing Chapter-11 Dual Nature of Radiation and Matter NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON DUAL NATURE OF RADIATION AND MATTER

Question 1: A strong argument for the particle nature of cathode rays is that they

(a) produce fluorescence
(b) travel through vacuum
(c) get deflected by electric and magnetic fields
(d) cast shadow

Answer=C

Question 2 : In an electron gun the control grid is given a negative potential relative to cathode in order to

(a) decelerate electrons
(b) repel electrons and thus to control the number of electrons passing through it
(c) to select electrons of same velocity and to converge them along the axis.
(d) to decrease the kinetic energy of electrons

Answer=B

Question 3: When the speed of electrons increase, then the value of its specific charge

(a) increases
(b) decreases
(c) remains unchanged
(d) increases up to some velocity

Answer=B

Question 4: Photoelectric effect is the phenomenon in which

(a) photons come out of a metal when it is hit by a beam of electrons.
(b) photons come out of the nucleus of an atom under the action of an electric field.
(c) electrons come out of a metal with a constant velocity
(d) which depends on the frequency and intensity of incident light wave.

Answer=D

Question 5 : The photoelectrons emitted from a metal surface are such that their velocity

(a) is zero for all
(b) is same for all
(c) lies between zero and infinity
(d) lies between zero and a finite maximum

Answer=D

Question 6 : Photoelectric emission occurs only when the incident light has more than a certain minimum

(a) power   

(b) wavelength
(c) intensity

(d) frequency

Answer=D

Question 7: When light is incident on a metal surface the maximum kinetic energy of emitted electrons

(a) vary with intensity of light
(b) vary with frequency of light
(c) vary with speed of light
(d) vary irregularly

Answer=B

Question 8: A photoelectric cell is a device which

(a) converts light into electricity
(b) converts electricity into light
(c) stores light
(d) stores electricity

Answer=A

Question 9 : The maximum energy of electrons released in a photocell is independent of

(a) the frequency of the incident light
(b) the intensity of the incident light
(c) the nature of the cathode
(d) All of the above

Question 10: The work functions of Silver and Sodium are 4.6 and 2.3 eV, respectively. The ratio of the slope of the stopping potential versus frequency plot for Silver to that of Sodium is

(a) 1

(b) 2

(c) 4

(d) zero

Answer=A

Question 11: In a photoelectric experiment the stopping potential for the incident light of wavelength 4000Å is 2 volt. If the wavelength be changed to 3000 Å, the stopping potential will be

(a) 2 V

(b) zero
(c) less than 2 V

(d) more than 2 V

Answer=D

Question 12: A photocell is illuminated by a small bright source placed 1 m away. When the same source of light is placed 2 m away, the number of electrons emitted by photocathode are reduced by a factor of

(a) 1/8

(b) 1/16

(c) 1/2

(d) 1/4

Answer=D

Question 13: Light from a hydrogen discharge tube is incident on the cathode of a photoelectric cell, the work function of the cathode surface is 4.2 eV. In order to reduce the photocurrent to zero the voltage of the anode relative to the cathode must be made

(a) – 4.2 V

(b) – 9.4 V

(c) – 17.8 V

(d) + 9.4 V

Answer=B

Question 14: In Davison-Germier experiment, an electron beam is incident on a crystal. The reflected beam consists of

(a) photons

(b) protons
(c) x-rays

(d) electrons

Answer=D

Question 15: In the Davisson and Germier experiment, the velocity of electrons emitted from the electron gun can be increased by

(a) increasing the potential difference between the anode and filament
(b) increasing the filament current
(c) decreasing the filament current
(d) decreasing the potential difference between the anode and filament

Answer=A