The following particle are moving with the same velocity, then maximum de-Broglie wavelength will be for
proton
α-particle
neutron
β-particle
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
An electron moves with a velocity 1 ×103 m/s in a magnetic field of induction 0.3 T at an angle 30o. If of electron is 1.76 × 1011 C/kg, the radius of the path is nearly
10-8 m
2 × 10-8 m
10-6 m
10-10 m
A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m, then
each emitted electron carries half the initial energy
number of electrons emitted is a quarter of the initial number
each emitted electron carries one quarter of the initial energy
number of electrons emitted is half the initial number
The energy of a photon of light is 3 eV. Then the wavelength of photon must be
4125 nm
412.5 nm
41250 nm
4 nm
The energy of a photon of wavelength λ is
hcλ
Which of the following is true ?
The stopping potential increases with increasing intensity of incident light
The photo current increases with increasing intensity of light
The current in photocell increases with increasing frequency of light
The photo current is proportional to applied voltage
Light of wavelength 5000Å falls on a sensitive plate with photoelectric work function of 1.9 eV. The kinetic energy of the photo electron emitted will be
0.58 eV
2.48 eV
1.24 eV
1.16 eV
When intensity of incident light increases
photo current increases
photo current decreases
kinetic energy of emitted photoelectrons increases
kinetic energy of emitted photo electrons decreases
Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per second on the average at a target irradiated by this beam is
9 × 1017
3 × 1016
9 × 1015
3 × 1019
