The momentum of a photon of energy 1 MeV in kg m/s, will be
0.33 × 106
7 × 10-24
10-22
5 × 10-22
Number of ejected photoelectron increases with increase
in intensity of light
in wavelength of light
in frequency of light
Never
The momentum of a photon of an electromagnetic radiation is 3.3 × 10-29 kg-ms-1 . What is the frequency of the associated waves ?
(h = 6.6 × 10-34 J-s, c = 3 × 108 ms-1 )
1.5 ×1013 Hz
7.5 ×1012 Hz
6.0 ×1013 Hz
3.0 ×103 Hz
In photoelectric effect, the work function of a metal is 3.5 eV. The emitted electrons can be stopped by applying a potential of - 1.2 V. Then
the energy of the incident photons is 4.7 eV
the energy of the incident photons is 2.3 eV.
if higher frequency photons be used, the photoelectric current will rise
when the energy of photos is 3.5 eV, the photoelectric current will be maximum
A photocell employs photoelectric effect to convert
change in the frequency of light into a change in electric voltage
change in the intensity of illumination into a change in photoelectric current
change in the intensity of illumination into a change in the work function of the photocathode
change in the frequency of light into a change in the electric current
Doubly ionised helium atoms and hydrogen ions are accelerated from rest through the same potential dop. The ratio of the final velocities of the helium and the hydrogen ion is
2
J J Thomson's cathode ray tube experiment demonstrated that
the e/m of electrons is greater than the e/m of protons
the e/m ratio of the cathode ray particles changes when a different gas is placed in the discharge tube
cathode rays are streams of negatively charged ions
all the mass of an atom is essentially in the nucleus
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
An ionization chamber with parallel conducting plates as anode and cathode has 5 × 107 electrons and the same number of single charge positive ions per cm3. The electrons are moving towards the anode with velocity 0.4 m/s. The current density from anode to cathode is 4 μ A/m2. The velocity of positive ions moving towards cathode is
0.4 m/s
1.6 m/s
zero
0.1 m/s
The figure shows a plot of photocurrent versus anode potential for a photo sensitive surface for three different radiations. Which one of the following is a correct statement ?
Curves a and b represent incident radiations of different frequencies and different intensities
Curves a and b represent incident radiations of same frequency but of different intensities
Curves b and c represent incident radiations of different frequencies and different intensities
Curves b and c represent incident radiations of same frequency having same intensity
