Question

Infrared radiation is also called IR. Describe how it is different from visible light. What emits IR? Can animals use it? Explain how emission of IR sometimes “wastes” energy. Give examples showing how IR is used in modern technology.

Answer 1

Infrared Radiation consists of electromagnetic waves with wavelengths ranging from 700 nm to 1 mm. These radiations cannot be detected by human eye. On the other hand, visible light consists of electromagnetic waves ranging from 380 nm to 700 nm. These radiations can be detected by human eye.

IR are also known as thermal radiations. All objects emit and absorb IR. The hotter the object, the more IR it will emit. Dark surfaces are good emitters of IR.

Some animals have the ability to sense IR, known as IR vision. These animals have specialised IR sensing organs known as pit organs. For example: snake, mosquitoes, bed bugs and vampire bats are kind of animals that uses IR sensing to track their prey or any potential danger approaching them.

Infrared radiations are associated with thermal energy. In most of the devices, emission of thermal energy is waste of energy. For example: a light bulb generates heat along with light energy on passage of electricity. Now this heat energy is not a useful energy and gets wasted in the environment.

Use of IR in Modern technology:

1. It is used in heat sensitive thermal imaging cameras. They are used to study heat patterns of humans and animals. They are also used as night cameras.

2. IR is used in gas monitoring and analyzing systems. These systems are used for testing air samples to see what gases are contained in that sample.

3. It is used in thermal imaging and thermal motion detection. Thermal imaging is used by firefighters to see where a burning building is too hot to safely enter. Thermal imaging is used for space imaging and to know the temperature of distant stars.