The velocity of electromagnetic radiation in a medium of permittivity ε0 and permeability μ0 is given by
A signal emitted by an antenna from a certain point can be received at another point of the surface in the form of
Sky wave
Ground wave
Sea Wave
Both (a) and (b)
Which of the following is the longest wave?
x-rays
y-rays
Microwaves
Radiowaves
Which of the following has minimum wavelength?
X-rays
Ultraviolet rays
Y-rays
Cosmic rays
Which of the following rays are not electromagnetic waves?
β-rays
Heat rays
Electromagnetic waves are
transverse waves
longitudinal waves
produced by charges moving with constant velocity
none of the above
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
A TV tower has a height of 100 m. How much population is covered by the TV broadcast if the average population density around the tower is 1000 km-2 (radius of earth = 6370 km)?
4,00,000
4,000
40,000
40,000,00
The velocity of electromagnetic wave is along the direction of
The frequency of y-rays, X-rays and ultraviolet rays are a, b and c respectively. Then
a>b>c
a
a=b-c
a>c>b
