Question

Thermal radiation exist in which part of electromagnetic spectrum?

• A. Ultraviolet
• B. Infrared
• C. Visible
• D. Violet

Hint:

Heat radiation = Infrared radiation.

Answer 1

The Correct Option is B

Thermal radiation refers to the electromagnetic radiation emitted by all objects with a temperature above absolute zero. The characteristic of thermal radiation is that it depends on the temperature of the emitting body.

The question asks which part of the electromagnetic spectrum thermal radiation primarily exists in. Let's analyze the options:

1. Ultraviolet: The ultraviolet region of the electromagnetic spectrum has shorter wavelengths and higher energy compared to visible light. It is not typically associated with thermal radiation.
2. Infrared: The infrared region has longer wavelengths compared to visible light and is strongly associated with the heat emitted by objects, making it the primary component of thermal radiation.
3. Visible: While some part of thermal radiation is visible when objects are hot enough to emit visible light (like a glowing piece of coal), thermal radiation mainly occurs in the infrared region.
4. Violet: This refers to the shortest wavelength of the visible spectrum, which also is not the primary component of thermal radiation.

Based on this analysis, thermal radiation primarily exists in the Infrared region of the electromagnetic spectrum.

The correct answer is therefore Infrared.