Infrared Radiation Questions

The electromagnetic spectrum includes all types of radiation. It includes short wavelength radiations like Gamma, X-rays, and ultraviolet, along with long-wavelength radiations like radio, microwaves and infrared.

Infrared radiation ranges from 700 nanometres (nm) to 1 millimetre (mm). Waves higher than visible light and shorter than radio waves are known as infrared radiations.

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Important Infrared Radiation Questions with Answers

1. What is the frequency range of infrared radiation?

The frequency range of infrared radiation is 10¹³ – 10¹⁴ Hz.

2. The branch of science that studies the interactions of electromagnetic waves with matter is _______.

1. Archaeology
2. Palaeontology
3. Spectroscopy
4. Bioscopy

Answer: c) Spectroscopy

Explanation: Spectroscopy is the study of the interaction of light and matter.

3. State true or false: Microwaves are used in night vision goggles.

1. TRUE
2. FALSE

Answer: b) FALSE

Explanation: Infrared radiations are used in night vision goggles to enable clear and bright images in the dark.

4. How is infrared radiation classified?

Infrared radiation is classified as short-wavelength, mid-wavelength, near-wavelength, far-infrared, and long-wavelength.

5. Choose YES or NO: Infrared radiations have a heat-inducing property.

1. YES
2. NO

Answer: a) YES

Explanation: Since infrared radiations have a heat-inducing property, it is used for therapeutic purposes or infrared heaters.

6. Who found infrared radiation?

1. Newton
2. Michel Faraday
3. Sir William Herschel
4. Kepler

Answer: c) Sir William Herschel

Explanation: In 1800, Sir William Herschel discovered infrared radiation.

7. Which type of infrared radiation is used in TV remote sensors?

1. Far-infrared rays
2. Near-infrared rays

Answer: b) Near-infrared rays

Explanation: TV remotes use near-infrared rays.

8. What is the wavelength range of short wavelength infrared?

1. 1.4 to 3 micrometres
2. 0.75 to 1.4 micrometres
3. 3 to 8 micrometres
4. 15 to 1000 micrometres

Answer: b) 0.75 to 1.4 micrometres

Explanation: The wavelength range of short wavelength infrared radiation is 0.75 to 1.4 micrometres.

9. Which among the following is used in astronomical telescopes and optical fibre communications?

1. Long-wavelength infrared
2. Medium infrared
3. Near-infrared
4. Far infrared

Answer: a) Long-wavelength infrared

Explanation: Astronomical telescopes and optical fibre communications are possible with the help of long-wavelength infrared.

10. Which among the following is used in cancer therapy?

1. Long-wavelength infrared
2. Medium infrared
3. Near-infrared
4. Far infrared

Answer: d) Far infrared

Explanation: Far infrared radiation is mainly used in cancer therapy.

Know about the electromagnetic spectrum in detail by watching this video.

Practice Questions

1. What is infrared radiation?
2. Explain in brief the electromagnetic spectrum.
3. What are the types of infrared radiations?
4. What is the wavelength range of medium infrared radiations?
5. List the properties of infrared waves.