NEET Physics Dual Nature of Radiation and Matter MCQs Set A

Question: The wavelength of a photon needed to remove a proton from a nucleus which is bound to the nuclear with 1 MeV energy is nearly
a) 1.2 × 10^–3 nm
b) 1.2 × 10 nm
c) 1.2 nm
d) 1.2 × 10^–6 nm
Answer: 1.2 × 10^–3 nm

Question: Consider a beam of electrons (each electron with energy E₀) incident on a metal surface kept in an evacuated chamber. Then,
a) electrons can be emitted with any energy, with a maximum of E₀
b) None of these
c) electrons can be emitted but all with an energy, E₀
d) no electrons will be emitted as only photons can emit electrons
Answer:  electrons can be emitted with any energy, with a maximum of E₀

Question:

a) will be less than the earlier value
b) will be the same as the earlier value
c) None of these
d) will depend on the target
Answer:  will be less than the earlier value

Question:

a)

b)

c)

d)

Answer:

Question:

a) remains constant
b) increases and decreases periodically
c) increases with time
d) None of these
Answer:  remains constant

Question:

a)

b) None of these

c)

d)

Answer:

Question:

a)

b)

c) Both
d) None of these
Answer:

Question:  When the energy of the incident radiation is increased by 20%, the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5 eV to 0.8 eV. The work function of the metal is :
a) 1.0 eV
b) 1.3 eV
c) 1.5 eV
d) 0.65 eV
Answer: 1.0 eV

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

Question:  A 15.0 eV photon collides with and ionizes a hydrogen atom. If the atom was originally in the ground state (ionization potential =13.6 eV), what is the kinetic energy of the ejected electron?
a) 1.4 eV
b) 13.6 eV
c) 28.6 eV
d) 15.0 eV
Answer: 1.4 eV

Question:  Light of wavelength 500 nm is incident on a metal with work function 2.28 eV. The de Broglie wavelength of the emitted electron is

a)

b)

c)

d) None of these

Answer:

Question:  Assertion : Photoelectric saturation current increases with mthe increase in frequency of incident light.
Reason : Energy of incident photons increases with increase in frequency and as a result photoelectric current increases.
a) Assertion is incorrect, reason is correct
b) Assertion is correct, reason is incorrect
c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
d) Assertion is correct, reason is correct; reason is a correct explanation for assertion
Answer: Assertion is incorrect, reason is correct

Question: Assertion : In process of photoelectric emission, all emitted electrons do not have same kinetic energy.
Reason : If radiation falling on photosensitive surface of a metal consists of different wavelength then energy acquired by electrons absorbing photons of different wavelengths shall be different.
a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
c) Assertion is correct, reason is incorrect
d) Assertion is incorrect, reason is correct.
Answer: Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Question:  When 0.50 Å X-rays strike a material, the photoelectrons from the k shell are observed to move in a circle of radius 23 mm in a magnetic field of 2 × 10^–2 tesla acting perpendicularly to the direction of emission of photoelectrons. What is the binding energy of k-shell electrons?
a) 6.2 keV
b) 2.9 keV
c) 5.5 keV
d) None of these
Answer: 6.2 keV

Question:  An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is :

a)

b)

c)

d)

Answer: