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
Which of the following rays are not electromagnetic waves?
β-rays
Heat rays
X-rays
y-rays
Which one of the following electromagnetic radiations have the smallest wavelength?
Ultraviolet waves
Microwaves
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
cosmic rays
sky wave
sea wave
both (a) and (b)
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
The velocity of electromagnetic wave is along the direction of
The structure of solids is investigated by using
infrared radiations
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 lakh
40,000
4000
40 lakh
In a certain region of space electric file and magnetic field are perpendicular to each other and an electron enters in region perpendicular to the direction of and both and moves undeflected, then velocity of electron is
