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)
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 velocity of electromagnetic wave is along the direction of
The structure of solids is investigated by using
infrared radiations
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 charging current for a capacitor at any instant is 0.25 A.The displacement current across the capacitor plates at that instant is
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 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 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
