CBSE
Multiple Choice QuestionsCalculate the kinetic energy of the electron having wavelength 1 nm
2.1 eV
3.1 eV
1.5 eV
4.2 eV
If velocity of a particle is three times of that of electron and ratio of de Broglie wavelength of particle to that of electron is 1.814 x 10-4. The particle will be
Neutron
Deuteron
Alpha
Tritium
Assertion: An electron microscope is based on de Broglie hypothesis.
Reason: A beam of electrons behaves as a wave which can be converged by electric and magnetic lenses.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
If the energy, E = Gp hq cr, where G is the universal gravitational constant, h is the Planck's constant, h is the Planck's constant and c is the velocity of light, then the values of p, q and r respectively
-1/2, 1/2 and 5/2
1/2, -1/2 and -5/2
-1/2, 1/2 and 3/2
1/2, -/2 and -3/2
The light of wavelength 4000 Ao falls on a photosensitive substance whose work function is 2 eV. Its stopping potential is
1.1 V
1.8 V
1.26 V
0.8 V
Assertion: There is a physical significance of matter waves.
Reason: Both interference and diffraction occurs in it.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: The de Broglie equation has significance for any microscopic or submicroscopic particles.
Reason: The de Broglie wavelength inversely proportional to the mass of the object if velocity is constant.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false.
If both assertion and reason are false.
de Broglie wavelength λ associated with neutrons is related with absolute temperature T as
λ ∝ T
λ ∝
λ ∝
λ ∝ T2
If we assume kinetic energy of a proton is equal to energy of the photon, the ratio of de Broglie wavelength of proton to photon is proportional to
E
E-1/2
E1/2
E3/2
If K1 and K2 are maximum kinetic energies of photoelectrons emitted when lights of wavelengths λ1 and λ2 respectively incident on a metallic surface. If λ1 = 3λ2, then
K1 > ( K2 / 3)
K1 < ( K2/3)
K1 = 2 K2
K2 = 2K1
