Electromagnetic Waves Multiple Choice Questions and Answers

(1) The distance in EDM is measured by______________

[A] Phase difference

[B] Amplitude

[C] Frequency of the wave

[D] Wave length

Answer: Phase difference

(2) Tellurometer, a type of EDM uses which of the following waves?

[A] Radio waves

[B] Micro waves

[C] Visible rays

[D] Infra-red waves

Answer: Radio waves

(3) Electromagnetic waves are represented in which of the following format?

[A] Sinusoidal waves

[B] Longitudinal waves

[C] Transverse waves

[D] None

Answer: Sinusoidal waves

(4) What would be the value of length if the distance is given as 30m, m= 3 and the change in length is 8m.

[A] 7.34m

[B] 5.43m

[C] 7.43m

[D] None of these

Answer: 7.34m

(5) What is the wavelength of light waves if their frequency is 5.0X1014 Hz?

[A] 0.60 micro-m

[B] 0.60 m

[C] 6.0 mm

[D] 0.060 mm

Answer: 0.60 micro-m

(6) What frequency are 20 mm microwaves?

[A] 15 GHz

[B] 73 GHz

[C] 100 MHz

[D] None of these

Answer: 15 GHz

(7) What is the wavelength of a signal with a frequency of 150Mhz?

[A] 2m

[B] 20m

[C] 10m

[D] None of these

Answer: 2m

(8) What is the frequency of the EM wave with a wavelength of 12cm?

[A] 2.5Ghz

[B] 0.25Mhz

[C] 2.4Ghz

[D] None of these

Answer: 2.5Ghz

(9) SHF Em waves are used in?

[A] Satellite communication

[B] Underwater communication

[C] Ground to ground communication

[D] Aircraft to ATC communication

Answer: Satellite communication

(10) Which one of the following is not a reason for not using X-rays in communication?

[A] High power is required

[B] Stopped by ionizing effects

[C] Highly attenuated

[D] None of these

Answer: Stopped by ionizing effects

(11) The portion of the electromagnetic spectrum occupied by a signal is called ________

[A] Bandwidth

[B] Signal spectrum

[C] Signal strength

[D] Frequency width

Answer: Bandwidth

(12) Infrared radiation was discovered in 1860 by:

[A] William Herschel

[B] Thomas Young

[C] William Wallaston

[D] None of above

Answer: William Herschel

(13) Which of the following rays is emitted by a human body?

[A] IR-rays

[B] UV-rays

[C] X-rays

[D] Visible rays

Answer: IR-rays

(14) A free electron is placed in the path of a plane electromagnetic wave. The electron will start moving:

[A] along the direction of propagation of the wave

[B] in a plane containing the magnetic field and the direction of propagation

[C] along the electric field

[D] along the magnetic field

Answer: along the electric field

(15) Electromagnetic waves ware transverse in nature is evident by:

[A] diffraction

[B] interference

[C] polarization

[D] reflection

Answer: polarization

(16) The rms value of the electric field of the light coming from the sun is 720 N/C. The average total energy density of the electromagnetic wave is:

[A] 6.37×10–9 J/m3

[B] 3.3×10–3 J/m3

[C] 4.58×10–6 J/m3

[D] 81.35×10–12 J/m3

Answer: 6.37×10–9 J/m3

(17) All electromagnetic waves travel through a vacuum at

[A] speeds that are inversely proportional to their frequency

[B] speeds that are proportional to their frequency

[C] the same speed

[D] None of the above

Answer: the same speed

(18) The E and B fields in electromagnetic waves are oriented

[A] perpendicular to the wave's direction of travel, and also to each other

[B] perpendicular to the wave's direction of travel, and parallel to each other

[C] parallel to the wave's direction of travel, as well as to each other

[D] None

Answer: perpendicular to the wave's direction of travel, and also to each other

(19) Which of the following correctly lists electromagnetic waves in order from longest to shortest wavelength?

[A] television, infrared, visible light, X-rays

[B] gamma rays, ultraviolet, infrared, microwaves

[C] microwaves, ultraviolet, visible light, gamma rays

[D] radio waves, infrared, gamma rays, ultraviolet

Answer: television, infrared, visible light, X-rays

(20) Modern EDM uses which among the following waves?

[A] Visible rays

[B] Modulated infra-red

[C] Radio waves

[D] None of these

Answer: Modulated infra-red

Electromagnetic Waves MCQs | Electromagnetic Waves Multiple Choice Questions and Answers

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Electromagnetic Waves MCQs | Electromagnetic Waves Multiple Choice Questions and Answers

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