### MCQs of Electromagnetic Waves

Showing 1 to 10 out of 112 Questions
1.
Astronomers have found that the electromagnetic waves of wavelength 21 cm are continuously reaching the Earth's surface. The frequency of this radiation is _____ . (c = 3 × 108 ms-1 )
 (a) 1.43 GHz (b) 1.43 MHz (c) 1.43 kHz (d) 1.43 Hz
2.
In Hertz's experiment the _____ of the electromagnetic waves is equal to the kinetic energy of the charges oscillating between the two spheres.
 (a) frequency (b) energy (c) wavelength (d) velocity
3.
The electromagnetic waves in the range of wavelengths from 3 mm to 100 cm are used for the purpose of satellite communication. The range of frequencies corresponding to this range of wavelengths is _____ .(c = 3 × 108 ms-1 )
 (a) 30 MHz to 104 MHz (b) 300 MHz to 105 MHz (c) 3 MHz to 3 × 108 MHz (d) 3 MHz to 106 MHz
4.
If vg, vx and vm are the velocities of the γ-rays, X- rays and microwaves respectively in space, then
 (a) vg > vx > vm (b) vg < vx < vm (c) vx > vm > vg (d) vg = vx = vm
5.
If ${\mu }_{r}$ be relative permeability and K be dielectric constant of a given medium, then the refractive index of the medium is n = _____ .
 (a) (b) (c) (d) $\sqrt{\frac{{\mu }_{r}}{K}}$
6.
 (a) 3 × 10-6 T (b) 6 × 10-8 T (c) 9 × 10-9 T (d) 2 ×10-10 T
7.
 (a) (b) (c) (d)
8.
 (a) (b) (c) (d)
9.
Two opposite charged particles oscillate about their mean equilibrium position in free space, with a frequency of 109 Hz. The wavelength of the corresponding electromagnetic wave produced is _____ .
 (a) 0.3 m (b) 3 × 1017 m (c) 109 m (d) 3.3 m
10.
The wavelengths 5890 Å and 5896 Å of sodium doublet correspond to ________ region the electromagnetic spectrum.
 (a) infrared (b) visible light (c) ultraviolet (d) microwave
Showing 1 to 10 out of 112 Questions