NEET Physics Photon Photoelectric Effect X rays and Davison Germer Experiment MCQs

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

Question: The photoelectrons emitted from a metal surface are such that their velocity
a) lies between zero and a finite maximum
b) lies between zero and infinity
c) is same for all
d) is zero for all
Answer: lies between zero and a finite maximum

Question: In which of the following, emission of electrons does not take place?
a) X-rays emission
b) Secondary emission
c) Thermionic emission
d) Photoelectric emission
Answer: X-rays emission

Question: Photoelectric emmision occurs only when the incident light has more than a certain minimum
a) frequency
b) wavelength
c) intensity
d) power
Answer: frequency

Question: The energy of a photon of green light of wavelength 5000Å is
a) 3.973 × 10^–19 joule
b) 8453 × 10^–19 joule
c) 3.459 × 10^–19 joule
d) None of these
Answer: 3.973 × 10^–19 joule

Question:  Which of the following when falls on a metal will emit photoelectrons ?
a) UV radiations
b) Infrared radiation
c) Microwaves
d) Radio waves
Answer: UV radiations

Question: The work-function of a metal is
a) the minimum amount of energy required to take out the electron from the metal surface
b) None of these
c) the maximum frequency required to take out electron from the metal surface
d) the minimum current required to take out electron bfrom the metal surface
Answer:  the minimum amount of energy required to take out the electron from the metal surface

Question:  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) (iii) only
b) (i) and (iv) only
c) (ii) and (iii) only
d) (ii) only
Answer: (iii) only

Question: The stopping potential is directly related to
a) the kinetic energy gained by the photoelectrons
b) the saturation current for the given frequency
c) intensity of incident radiation
d) the work function of the metal
Answer:  the kinetic energy gained by the photoelectrons

More Questions.....................................

Question:  When light is incident on a metal surface the maximum kinetic energy of emitted electronsa) vary with frequency of light
b) vary with intensity of light
c) vary with speed of light
d) vary irregularly
Answer: vary with frequency of light

Question: 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

Question: The maximum energy of electrons released in a photocell is independent of
a) the nature of the cathode
b) All of the above
c) the intensity of the incident light
d) the frequency of the incident light
Answer:  the nature of the cathode

Question:  Light of a particular frequency n is incident on a metal surface. When the intensity of incident radiation is increased, the photoelectric current
a) increases
b) decreases
c) sometimes increases and sometimes decreases
d) remains unchanged
Answer: increases

Question:  The work function of a metal is independent of
(i) nature of the surface of the metal
(ii) dimensions of the metal
(iii) properties of the metal
(iv) abundance of the metal
a) (ii) and (iv)
b)  (i) and (iii)
c) (ii) and (iii)
d) (i) only
Answer:  (ii) and (iv)

Question: The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately
a) 310 nm
b) 400 nm
c) 540 nm
d) 220 nm
Answer: 310 nm