We consider the radiation emitted by the human body. Which of the following statements is true:
- The radiation emitted is in the infrared region
- The radiation is emitted only during the day
- The radiation is emitted during the summers and absorbed during the winters
- The radiation emitted lies in the ultraviolet region and hence is not visible
The Correct Option is A
Solution and Explanation
Option (A) is correct. Human body radiation primarily falls within the infrared part of the electromagnetic spectrum, which is why thermal imaging devices can detect and visualize this radiation. The radiation is related to the warmth of the human body.
Options (B), (C), and (D) are incorrect:
(B) The radiation is not emitted only during the day. The human body continuously emits infrared radiation as long as it has a temperature above absolute zero. It is not dependent on whether it's day or night.
(C) The radiation emitted by the human body is not dependent on the seasons (summers or winters). It occurs all year round and depends on the individual's body temperature.
(D) The radiation is not in the ultraviolet region; it's in the infrared region. Ultraviolet radiation has shorter wavelengths and is not associated with the human body's thermal radiation.
So, the correct option is (A): The radiation emitted is in the infrared region.
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Concepts Used:
Radiation
Radiation is the energy or particles from a source that travels from one media to other. It travels through a medium after its emission from a source and is absorbed by matter.
Forms of Radiation:
- Particle Radiation includes the alpha (α), beta (β), and neutron radiations.
- Gravitational Radiation includes the radiation that takes the form of gravitational waves or as ripples in the curvature of space-time.
- Acoustic Radiation includes ultrasound, seismic and sound waves.
- Electromagnetic Radiation is inclusive of radio waves, gamma radiation (γ), x-rays, and visible light.
Types of Radiation:
- Ionizing Radiation - It carries more than 10 eV, that is enough to ionize atoms and molecules and break chemical bonds.
- Non-ionizing Radiation – It consists of alpha particles, beta particles, and gamma particles, whereas ionizing radiation consists of microwave radiation, infrared radiation and radio waves.
Read More: Types of Radiation