250+ TOP MCQs on Remote Sensing – Electromagnetic Spectrum and Answers

Surveying Multiple Choice Questions on “Remote Sensing – Electromagnetic Spectrum”.

1. Energy of the discrete particles can be given by_______
a) Photons
b) Protoplasm
c) Electrons
d) Neutrons
Answer: a
Clarification: Photons act as a constituent particle in case of electromagnetic wave. These possess certain properties like energy and momentum which is able to deliver it to the wave and helps in certain classifications.

2. Which among the following is having more wavelengths?
a) X-rays
b) Cosmic waves
c) Radio waves
d) Gamma rays
Answer: c
Clarification: Radio waves possess the longest wavelength in the electromagnetic spectrum, which makes it suitable in the usage of classified radars for operating in a particular region.

3. Which among the following wave is not employed in case of remote sensing?
a) X-ray
b) Visible ray
c) Thermal IR
d) Radio waves
Answer: a
Clarification: Gamma rays, X-rays and UV rays will be absorbed by the atmosphere so that the sensor which is mounted on the satellite can’t use the facilities which can be provided by these rays and also these possess very less wavelength.

4. Optical mechanical scanner is used in which type of electromagnetic waves?
a) X-rays
b) Cosmic waves
c) Radio waves
d) Thermal IR
Answer: d
Clarification: Infrared region has been classified into thermal IR and reflected IR. Thermal IR is equipped with the optical mechanical scanner and a special system which is free from a film produces images by using wavelengths of range 3-5 micrometer.

5. Radio waves are having the longest wavelength among all the electromagnetic waves.
a) False
b) True
Answer: b
Clarification: In an electromagnetic spectrum, certain classifications were made to determine the wave properties. Among them, radio and television waves stand at last having a long wavelength parameter. This makes it suitable for usage of radars.

6. Gamma rays are having a wavelength of _________
a) Zero
b) Greater than 0.03nm
c) Less than 0.03nm
d) Equal to 0.03nm
Answer: c
Clarification: In an electromagnetic spectrum Gamma rays are having second least wavelength. It can be clearly observed that these rays are absorbed by the atmosphere which makes it possess least wavelength, which is less than 0.03nm.

7. Which of the following waves can be used in case of remote sensing?
a) UV rays
b) X-rays
c) Gamma rays
d) Visible rays
Answer: d
Clarification: Electromagnetic spectrum consists of a wide range of classifications among those some of them are absorbed by the atmosphere and most of them are used in remote sensing those include visible rays, IR rays, Radar waves, Radio waves etc.

8. Which of the following indicates the correct set of combination in radio waves?
a) Shorter wavelength – high frequency
b) Longer wavelength – less frequency
c) Shorter wavelength – less frequency
d) Longer wavelength – high frequency
Answer: a
Clarification: From the relation it can be clearly seen that wavelength and frequency are inversely proportional to each other which makes it form a relation that is shorter wavelength must possess high frequency which makes it suitable in case of cosmic rays and radio waves.

9. How much wave length is reflected back by the earth surface from the absorbed sun radiation?
a) 0.5meter
b) 0.5 micrometer
c) 0.5 centimeter
d) 0.5 decimeter
Answer: b
Clarification: In general, the radiation received from sun is distributed to all over the world in a manner that the entire radiation is useful. But some of this is reflected back, which is 0.5 micrometer, a minute one.

10. EM waves varies from ______ to ________
a) Meters to nano-meters
b) Meters to micro-meters
c) Nano to micro-meters
d) Centimeters to nano-meters
Answer: a
Clarification: The EM wave is continuum of energy, which under goes certain propagations. During this course, it may undergo some undulations which result in decrease of the wave length capacity. Generally, these vary from meters to nano-meters.

11. The formula of energy produced from the body can be given as _________
a) Q = h- c / λ
b) Q = h*c * λ
c) Q = h+ c / λ
d) Q = h*c / λ
Answer: d
Clarification: The energy propagated from the body can be determined by
Q = h*c / λ. From this, the wave length can be determined by having an energy value. This help in the determination of the wavelength by using plank’s constant.