Which of the following is the longest wave?
X-rays
y-rays
Microwaves
Radiowaves
Electromagnetic waves are
transverse waves
longitudinal waves
produced by charges moving with constant velocity
none of the above
Which of the following has minimum wavelength?
Ultraviolet rays
Cosmic rays
If a source is transmitting electromagnetic waves of frequency 8.2 × 106 Hz, then wavelength of the electromagnetic waves transmitted from the source will be
40.5 m
42.3 m
36.6 m
50.9 m
The charging current for a capacitor at any instant is 0.25 A.The displacement current across the capacitor plates at that instant is
0.5 A
0.25 A
2.5 A
1 A
What is the cause of "Green house effect"?
Infrared rays
Radio-waves
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 structure of solids is investigated by using
cosmic rays
infrared radiations
The velocity of electromagnetic radiation in a medium of permittivity ε0 and permeability μ0 is given by
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
