Electromagnetic Waves  MCQs

MCQs of Electromagnetic Waves

Showing 41 to 50 out of 112 Questions
41.
Which type of rays are produced during the nuclear reactions ?
(a) Gamma
(b) X - rays
(c) Infrared
(d) Ultraviolet
Answer:

Option (a)

42.

Match List - I (Electromagnetic wave type) with List - II (Its association/application) and select the correct option from the choices given below the lists.

  List - I   List - II
(a)  Infrared waves (i)  To treat muscular strain
(b)  Radio waves (ii)  For broadcasting
(c)  X - rays (iii)  To detect fracture of bones
(d)  Ultraviolet rays (iv)  Absorbed by the ozone layer of the atmosphere
(a) (a → iii), (b → ii), (c → i), (d → iv)
(b) (a → i), (b → ii), (c → iii), (d → iv)
(c) (a → iv), (b → iii), (c → ii), (d → i)
(d) (a → i), (b → ii), (c → iv), (d → iii)
Answer:

Option (b)

43.
During the propagation of electromagnetic waves in a medium :
(a) Electric energy density is equal to the magnetic energy density.
(b) Both electric and magnetic energy densities are zero.
(c) Electric energy density is double of the magnetic energy density.
(d) Electric energy density is half of the magnetic energy density.
Answer:

Option (a)

44.
A Red LED emits light 0.1 watt uniformly around it. The amplitude of the electric field of the light at a distance of 1 m from the diode is :
(a) 1.73 V/m
(b) 2.45 V/m
(c) 5.48 V/m
(d) 7.75 V/m
Answer:

Option (b)

45.
At room temperature, if the relative permittivity of water be 80 and the velocity of light in water is 2.25 × 108ms-1, then the relative permeability of water is _____
(a) 0.0022
(b) 0.222
(c) 0.0222
(d) 2.022
Answer:

Option (c)

46.
Arrange the following electromagnetic radiations per quantum in the order of increasing energy :

A : Blue light     B : Yellow light

C : X - ray         D : Radiowave

(a) D, B, A, C
(b) A, B, D, C
(c) C, A, B, D
(d) B, A, D, C
Answer:

Option (a)

47.
Capacitance of capacitor is 2pF. Electric field inside capacitor is changing with the rate of 1012 Vs-1 . Then displacement current is ____ A
(a) 2
(b) 3
(c) 6
(d) 9
Answer:

Option (a)

48.
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
Answer:

Option (b)

49.
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
Answer:

Option (d)

50.
If µr be relative permeability and K be the dielectric constant of a given medium, then the refractive index of the medium is n = _____ .
(a) μrK
(b) μoε0
(c) 1μrK
(d) μrK
Answer:

Option (a)

Showing 41 to 50 out of 112 Questions