- Infrared waves often known as heat waves as they are produced by hot bodies.
- Their wavelength is lesser than both radio and micro waves.
- They readily get absorbed by water.
Applications:- Infrared lamps/Infrared detector/LED in remote switches of electronic devices/Greenhouse effect.
- Fire gives out both visible light waves and infrared waves.The light rays are visible to us but the infrared wavescannot be seen by us.
- Humans also generate some infrared waves.
- There are some special glasses which have infrared detector to view infrared waves.
- The infrared lamps are used to heat food materials and sometimes washrooms.
- When we switch on the TV with the help of remote,there is an LED both on TV and on remote.
- The signal gets transferred from remote to TV viainfrared waves.
Greenhouse Effect:- Green house effect is an atmospheric heating phenomenon that allows incoming solar radiation to pass through but blocks the heat radiated back from the Earth’s surface.
- Consider that the sun gives radiation in the form of visible light to the earth.
- When the visible light reaches the earth’s surface all the objects on the earth becomes hot.
- The visible light carries energy from sun and that energy gets transferred to all the objects present on the earth.
- As a result of heat transfer all the objects gets heated up.
- These hot objects transmit infrared waves.
- The earth will reradiate the infrared waves.
- When these infrared waves try to go out of the atmosphere they get trapped by the greenhouse gases (CO2,CH4, water vapour).
- As a result heat gets trapped inside the earth which results in an increase in temperature.
- The greenhouse effect makes earth warm because of which the temperature of the earth is suitable for the survival of life on earth.
- Global warming is due toan increase in temperature of the environment, due to pollution.