Infrared Radiation - Electromagnetic Waves

,strong>Infrared radiation or IR also referred to as infrared, is a region of the electromagnetic radiation spectrum where the range of wavelengths is from about 700 nanometers to 1 millimetre. It is a type of radiant energy that is invisible to human eyes but that we can feel as heat.

What are Infrared Radiations?

The word infrared means below red. Red light has the longest wavelength that our eyes can see but infrared waves cannot be seen by the eye.

  • Infrared radiations are also referred to as heat or thermal waves or electromagnetic waves. This is because they have a heat inducing property. Sometimes infrared rays are used in applications where heat production is required like in infrared heaters or for therapeutic purposes where a patient requires physical therapy.
  • These waves have a wavelength range between 710 nm to 1 mm. Sometimes infrared rays themselves are classified as near infrared and far infrared rays.
  • Near-infrared rays are used in electronic applications like TV remote sensors and photography. Their applications can be somewhat similar to visible light applications since their wavelength ranges are close.
  • Far infrared rays are more thermal in nature. Anything generating heat gives out far infrared radiation. Even the human body (at \(37^{\circ}C\) ) gives off infrared radiations of around 800 nm wavelength.
Infrared Radiation

Infrared Radiation from the Sun

Medicinal Effect of Infrared Rays

There are various medicinal effect of infrared rays. Some are listed in the points below.

  • It plays an important aid in stress management.
  • It helps cure fatigue and cold. It is also helpful with the exhaustion of the human body.
  • It is useful to ease kidney function.
  • It reduces pain in herniated disc and arthritis.
  • It helps to reduce inflammation of throat, nose and ear.

Applications of Infrared Radiation

Infrared light can also term has thermal light. The light near a campfire or even the light of the sun, these kinds of lights also emit some thermal energy which causes you to feel the heat. Infrared heaters also come under this where they use infrared radiation to generate thermal energy.

Extended Reading List

Stay tuned with BYJU’S to read more about infrared radiation and other electromagnetic waves that form the electromagnetic spectrum and their wide range of applications with interactive videos to make learning simple.

Q1) What is infrared radiation?

Answer: Infrared radiation, also known as infrared is a region in the electromagnetic radiation spectrum where the wavelength range from 710 nm to 1 mm.

Q2) Infrared radiations have a wavelength range of _____.

  1. 710 nm to 1 mm
  2. 1mm to 50 mm
  3. 100 nm to 500 nm
  4. 100 mm to 1 m

Answer: a. 710 nm to 1 mm

Infrared radiations have a wavelength range of 710 nm to 1 mm.

Q3) Why do we use microwaves in the oven and not infrared radiation?

Answer:

Q4) List a few properties of infrared radiation.

Answer:

Following are a few properties of infrared radiation:

  1. Infrared radiation, like all radiation, travels at a speed of 299,792,458 meters per second.
  2. Infrared light can exhibit both wave and particle nature at the same time.
  3. Depending on the nature of the material that infrared radiation strikes, it can either be absorbed or reflected.
  4. Infrared radiation increases the thermal energy in particles.

Q5) List a few medicinal effects of infrared radiation.

Answer:

A few medicinal effects of infrared radiation are as follows:

  • Used to reduce the inflammation of throat, ear and nose
  • Used as an aid in stress management
  • Reduces pain arthritis
  • It eases kidney function

Q6) Infrared radiation excites vibrational motion in a molecule through the change in the _____.

  1. atom
  2. dipole moment
  3. sodium
  4. atomic bonds

Answer: b. dipole moment

The infrared radiation excites vibrational motion in a molecule through the change in the dipole moment.

Q7) Infrared waves have wavelengths shorter than visible and longer than microwaves.

  1. True
  2. False

Answer: b.False

Infrared waves have wavelengths longer than visible and shorter than microwaves.

Q8) Infrared frequencies have frequencies lower than visible and higher than microwaves.

  1. True
  2. False

Answer: a. True

Infrared frequencies have frequencies lower than visible and higher than microwaves.

Q9) How do we experience infrared radiation on a daily basis?

Answer:

Infrared is a type of radiant energy that is invisible to the eyes and we can only feel it in the form of heat. All objects in the universe emit some level of IR radiation. Sun and fire are among the most obvious source of infrared radiation.

Q10) Write a few applications of infrared radiation.

Answer:

  • Infrared radiations are used in thermography to remotely determine the temperature of objects.
  • Used in night vision equipment where there is insufficient visible light to see
  • Used to detect impurities


Practise This Question

Which radiation in sunlight, causes heating effect