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
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
Acceleration of an electron in the first Bohr orbit is proportional to
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
If h is Planck's constant, the momentum of a photon of wavelength 0.01 Å is
h × 10-2
h
h × 102
h × 1012
An electron is accelerated through a potential difference of 1000 volt. Velocity is nearly
3.8 × 107 m s-1
1.9 × 106 m s-1
1.9 × 107 m s-1
5.7 × 107 m s-1
wavelength λ is emitted. If we take into account the recoil of an atom, when a photon is emitted,
λ = λ0
λ < λ0
λ > λ0
The data is not sufficient to reach a conclusion.
Gases begin to conduct electricity at low pressure because
at low pressures gases turn to plasma
colliding electrons can acquire higher kinetic energy due to increased mean free path leading to ionisation of atoms
atoms break up into electrons and protons
the electrons in atoms can move freely at low pressures
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
Bragg's equation will have no solution, if
λ > 2d
λ < 2d
λ < d
λ = d
