CBSE
Multiple Choice QuestionsThe ratio of the dimensions of Planck's constant and that of the moment of inertia is the dimension of
frequency
velocity
angular momentum
time
The light rays having photons of energy 1.8 eV are falling on a metal surface having a work function 1.2 eV. What is the stopping potential to be applied to stop the emitting electrons?
3 eV
1.2 eV
0.6 eV
1.4 eV
A light passing through air has wavelength 6000 Ao. The wavelength when same ray passes through a glass slab of refractive index 1.5 will be:
2000 Ao
4000 Ao
8000 Ao
1200 Ao
A leaf which contains only green pigments, is illuminated by a laser light of wavelength 6328 pm. It would appear to be
brown
black
red
green
The minimum wavelength of X-ray emitted by X-ray tube is 0.4125 Ao. The accelerating voltage is
30 kV
50 kV
80 kV
60 kV
The nuclei of which one of the following pairs
of nuclei are isotones ?
A photosensitive metallic surface has work function, h vo, If photons of energy 2hvo, fall on this surface, the electrons come out with a maximum velocity of 4 x 106 m/s. When the photon energy is increased to 5 hv,, then maximum velocity of photoelectrons will be
2 × 106 m/s
2 × 107 m/s
8 × 105 m/s
8 × 106 m/s
In photoelectric effect, the electrons are ejected from metals if the incident light has a certain minimum
wavelength
frequency
amplitude
angle of incidence
The work functions for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein's equation, the metals which will emit photoelectrons for a radiation length 4100 Ao is /are
none
A only
A and B only
all the three metals
Hard X-rays for the study of fractures in bones should have a minimum wavelength of 10' m. The accelerating voltage for electrons in X-ray machine should be
< 124 kV
> 124 kV
between 60 kV and 70 kV
= 100 kV
