CBSE
Multiple Choice QuestionsAn electron beam is accelerated through a potential difference of V volt. The minimum wavelength of X-rays produced is :
Light waves of wavelength is incident on a metal of work function . Maximum velocity of the electron is :
Spectrum of a star is shifting towards voilet colour, then the star
is going away from earth
is coming towards earth
intensity of light of star is increasing
intensity of light of star is decreasing
X-rays are not used for radar purposes because they are not
reflected by target
partly absorbed by target
electromagnetic waves
completely absorbed by target
The minimum wavelength of X-ray emitted by X-ray tube is 0.4125 . The accelerating voltage is
30 kV
50 kV
80 kV
60 kV
The nature of light waves is similar to
cosmic rays
cathode rays
gamma rays
alpha rays
The energy of an X-ray photon is 2 keV, then its frequency will be
3.2 x 10-6 per second
5 x 1017 per second
2 x 1017 per second
2 × 1018 per second
The speed of electromagnetic waves in vaccum is
µ0ε0
An electromagnetic wave travels along Z- axis. The pair of space and time varying field is
Ey, Bx
By, Ez
Ex, By
Ez, Bx
Arrange the following electromagnetic radiation in the order of decreasing energy.
A. Infrared waves B. Ultraviolet rays
C. Orange light D. Green light
B, C, A, D
D, A, C, B
B, D, C, A
A, C, D, B
