GkSeries.com

NCERT Solutions for class 12 Physics | Chapter 11 - Dual Nature of Radiation and Matter

Download PDF

Free download in PDF Class 12 Physics Chapter 11 Dual Nature of Radiation and Matter Multiple Choice Questions and Answers for Board, JEE, NEET, AIIMS, JIPMER, IIT-JEE, AIEE and other competitive exams. MCQ Questions for Class 12 Physics with Answers were prepared based on the latest exam pattern. These short solved questions or quizzes are provided by Gkseries. These will help the students for preparation of their examination./p>

Go To Download Page
(1) K1 and K2 are maximum kinetic energies of photo electrons emitted when light having wavelengths λ1 and λ2 respectively incident on a metallic surface. If λ1 = 3λ2, then
[A] K1 < (K2/3)
[B] K1 > (K2/3)
[C] K1 = 3K2
[D] None of these
Answer: K1 < (K2/3)
(2) When light of wavelength λ strikes a photo sensitive surface, then the kinetic energy of ejected electrons is E. If the kinetic energy is to be changed to 2E then the wavelength should be changed to λ’. The correct relation between λ and λ’ is
[A] λ’ = λ
[B] λ’ =2 λ
[C] λ/2 < λ’< λ
[D] λ’ = λ/2
Answer: λ/2 < λ’< λ

DOWNLOAD CURRENT AFFAIRS PDF FROM APP

(3) The velocity of the most energetic electrons emitted from a metallic surface is doubled when the frequency (v) of incident radiation is double. What is the work function of this metal?
[A] zero
[B] hv/3
[C] hv/2
[D] 2hv/3
Answer: 2hv/3
(4) In a plot of the kinetic energy of the emitted photo electrons from a metal verses the frequency of the incident radiation gives a straight line whose slope
[A] depends on the nature of the metal used
[B] depends on the intensity of the radiation
[C] is the same for all metals and independent of the intensity of the radiation
[D] depends both on the intensity of the radiation and the metal used
Answer: is the same for all metals and independent of the intensity of the radiation
(5) Which of the following shows particle nature of light?
[A] Refraction
[B] Interference
[C] Polarization
[D] Photoelectric effect
Answer: Photoelectric effect
(6) A photoelectric cell is a device which
[A] converts light into electricity
[B] converts electricity into light
[C] stores light
[D] stores electricity
Answer: converts light into electricity
(7) 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: The work function of different metals is different.
(8) The minimum energy required to eject an electron, from the metal surface is called
[A] atomic energy
[B] mechanical energy
[C] electrical energy
[D] work function
Answer: The minimum energy required for the emission of electrons is called work function.
(9) In the photoeletric effect, electrons are emitted
[A] at a rate that is proportional to the amplitude of the incident radiation
[B] with a maximum velocity proportional to the frequency of the incident radiation
[C] at a rate that is independent of the emitter
[D] only if the frequency of the incident radiations is above a certain threshold value
Answer: Photoelectrons are emitted if the frequency of incident light is greater than the threshold frequency.
(10) Einstein’s photoelectric equation states that

hν = W0 + Ek.

In this equatin, Ek refers to the

[A] kinetic energy of all the emitted electrons
[B] mean kinetic energy of the emitted electrons
[C] maximum kinetic energy of the emitted electrons
[D] minimum kinetic energy of the emitted electrons
Answer: In the given relation Ek stands for maximum K.E. of emitted photoelectrons.
(11) 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
Answer: Max. K.E. of phtoelectrons emitted is independent of intensity of incident light.
(12) A photoelectric cell converts
[A] light energy into heat energy
[B] light energy to sound energy
[C] light energy into electric energy
[D] electric energy into light energy
Answer: Photoelectric cell converts light energy into electric energy.
(13) The photo-electrons 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: lies between zero and a finite maximum
(14) The momentum of a photon of wavelength λ is
[A] hλ
[B] h/λ
[C] λ/h
[D] h/cλ
Answer: h/λ
(15) In a photon-particle collision, the quantity that does not remain conserved is
[A] total energy
[B] total momentum
[C] number of photons
[D] None of these
Answer: number of photons
(16) The photoelectric effect is based on the law of conservation of
[A] momentum
[B] energy
[C] angular momentum
[D] mass
Answer: energy
(17) 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: vary with frequency of light
(18) Photons are deflected by
[A] electric field only
[B] magnetic field only
[C] electromagnetic field
[D] None of these
Answer: None of these
(19) The photoelectric current does not depend upon the

(i) frequency of incident light

(ii) work function of the metal

(iii) stopping potential

(iv) intensity of incident light

[A] (i) and (iv) only
[B] (ii) and (iii) only
[C] (iii) only
[D] (ii) only
Answer: (iii) only
(20) The theory of quantisation of electric charge was given by
[A] William Crookes
[B] J. J. Thomson
[C] R.A. Millikan
[D] Wilhelm Hallwachs
Answer: R.A. Millikan

Please share this page

Chapters

Click Here to Read more questions

Teacher Eligibility Test