Photoelectric effect supports quantum nature of light because
there is minimum frequency of light below which no photoelectrons are emitted
the maximum energy of photoelectron depends only on the frequency of light and not on its intensity
photoelectric effect is an instantaneous process
all the above choices are correct
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: 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 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
Calculate the kinetic energy of the electron having wavelength 1 nm
2.1 eV
3.1 eV
1.5 eV
4.2 eV
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
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.
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
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
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.
A.
If both assertion and reason are true and reason is the correct explanation of assertion.
The de Broglie equation relates a moving particle with its momentum. The de Broglie wavelength is the wavelength λ associated with a massive particle and related to its momentum p, through the Planck constant, h.
By the Einstein equation
E = mc2
E =
By equating
mc2 =
mc =
p =
By keeping h and m constatnt
We can understand p is inversely proportional to mass
Again p= wavelength / lamda / de brogelie wavelength.