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 of the following is the longest wave?
Electromagnetic waves are
transverse waves
longitudinal waves
produced by charges moving with constant velocity
none of the above
The ground state energy H-atom is 13.6 eV. The energy needed to ionize H –atom from its second excited state is
1.51 eV
3.4 eV
13.6 eV
12.1 eV
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
A signal emitted by an antenna from a certain point can be received at another point of the surface in the form of
both (a) and (b)
The structure of solids is investigated by using
infrared radiations
Which of the following has minimum wavelength?
X-rays
Ultraviolet rays
y-rays
Cosmic rays
In a plane electromagnetic wave, the electric field oscillates with a frequency of 2 × 1010 s-1 and an amplitude of 40 Vm-1. The wavelength of the wave is
3 × 10-3 m
2.5 × 10-2 m
1.5 × 10-2 m
4.5 × 10-3 m
The velocity of electromagnetic wave is along the direction of