What is the cause of "Green house effect"?
Infrared rays
Ultraviolet rays
X-rays
Radio-waves
The amplitudes of electric and magnetic fields in an electromagnetic wave are related to each other as
E0 = B0
E0 = cB0
E0 = B0 /c
E0 = c/B
Which one of the following electromagnetic radiations have the smallest wavelength?
y-rays
Ultraviolet waves
Microwaves
Ozone layer blocks the radiations of wave length
less than 3 × 10-7 m
equal to 3 × 10-7 m
more than 3 × 10-7 m
all of the above
Which of the following is the longest wave?
Radiowaves
The velocity of electromagnetic radiation in a medium of permittivity ε0 and permeability μ0 is given by
Which of the following rays are not electromagnetic waves?
β-rays
Heat rays
The frequency of electromagnetic wave, which is best suited to observe a particle of radius 3 × 10-4 cm, is of the order of
1015
1014
1013
1012
Which of the following has minimum wavelength?
Cosmic rays
If λv, λx and λm represent the wavelengths of visible light, X-rays and microwaves respectively, then
λm > λx > λv
λv > λm > λx
λm > λv > λx
λv > λx > λm
