The structure of solids is investigated by using
infrared radiations
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 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
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
What is the cause of "Green house effect"?
Infrared rays
Ultraviolet rays
X-rays
Radio-waves
Which of the following is the longest wave?
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 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 frequency of electromagnetic wave, which is best suited to observe a particle of radius 3 × 10-4 cm, is of the order of
The frequency of y-rays, X-rays and ultraviolet rays are a, b and c respectively. Then
