The nature of ions knocked out from hot surfaces is
protons
electrons
neutrons
nuclei
Einstein's work on photoelectric effect gives support to
E = mc2
E = hν
hν = 1/2 mv2
E = h/λ
The de - Broglie wave corresponding to a particle of mass m and velocity v has a wavelength associated with it is
h/mν
hmν
mh/ν
m/hν
When ultraviolet rays are incident on metal plate,the photoelectric effect does not occur.It occurs by incidence of
infrared rays
X -rays
radiowaves
light waves
Which of the following are thermions?
photons
positrons
Photon of frequency v has a momentum associated with it. If c is the velocity of light, the momentum is
v/c
hvc
hv/c2
hv/c
If the wavelength of Hα line of the Balmer series of the hydrogen spectum is λ the wavelength of the
Hβ line is 7/20 λ
Least energetic spectral line of the Lyman series is 5/27 λ
Ionisation potential of hydrogen is hc/λ
All the above are true
Monochromatic light incident on a metal surface emits electrons with kinetic energies from 0 to 2.6 eV. What is the least energy of the incident photon, if the tightly bound electrons needs 4.2 eV to remove?
1.6 eV
Between 1.6 eV and 6.8 eV
6.8 eV
More than 6.8 eV
In the phenomenon of electric discharge through gases at low pressure,the coloured glow in the tube appears as a result of
excitation of electrons in the atoms
collision between the atoms of the gas
collisions between the charged particles emitted from the cathode and the atoms of the gas
collision between different electrons of the atoms of the gas
Bragg's equation will have no solution, if
λ > 2d
λ < 2d
λ < d
λ = d
