A. 103 photons of wavelength 2 pm (γ-rays)
B. 102 photons of wavelength 1nm (x-rays)
C. 106 photons of wavelength 50?m (infrared)
D. 106 photons of wavelength 200nm (UV)
Modern Physics
Rest mass of a photon is________________?
A. infinite
B. zero
C. very small
D. 1.67 x 10-27 kg
Tick the right statement?
A. no photo electronic emission takes place if the frequency of radiation however intense it may be is less than a certain critical value called threshold frequency
B. threshold frequency depends upon the nature of the metal surface
C. maximum energy of a photoelectron is a function of frequency rather than intensity of radiation
D. all of the above
A photon is________________?
A. A unit of energy
B. A positively charged particle
C. A quantum of electromagnetic radiation
D. A unit of wavelength
If a material object moves with speed of light its mass becomes ________________?
A. equal to its rest mass
B. double of its rest mass
C. infinite
D. zero
An observer shoots parallel to a meter stick at very high (relativistic) speed and finds that the length of meter stick is________________?
A. greater than one meter
B. less than one meter
C. one meter
D. a foolish question
If a photon is reflected from the mirror then the change in momentum of each photon is_______________?
A. Zero
B. Double
C. Half
D. 1
In Compton scattering, the change in wavelength is maxed if_______________?
A. The angle of scattering is 90°
B. The angle of scattering is 60°
C. The angle of scattering is 180°
D. The angle of scattering is 0
A transmitting station emits radio waves of wavelength λ at power P. If h is Planck’s constant & c the speed of light what is the rate of emission of photons ?
A. λ
B. Speed of sound
C. Speed of lightB.
D. h
The existence of Ether wind was experimentally rejected by__________________?
A. equal to its rest mass
B. double of its rest mass
C. infinite
D. zero
