Advertisements
Advertisements
Questions
Why are infra-red waves often called heat waves? Explain.
Why are infrared waves often called heat waves? Given their one application.
Advertisements
Solution
Infrared waves are sometimes referred to as heat waves. This is because water molecules present in most materials readily absorb infrared waves (many other molecules, for example, CO2, and NH3, also absorb infrared waves). After absorption, their thermal motion increases, that is, they heat up and heat their surroundings.
Infrared waves are used in burglar alarms, security lights and remote controls for television and DVD players.
Notes
Students should refer to the answer according to their questions.
APPEARS IN
RELATED QUESTIONS
What role dose infra-red radiation play in maintain the Earth’s warmth
Name the subjective property of light related to its wavelength.
Give one use of microwaves.
Which part of electromagnetic spectrum is used in radar systems?
The short-wavelength limit shifts by 26 pm when the operating voltage in an X-ray tube is increased to 1.5 times the original value. What was the original value of the operating voltage?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.
Identify the part of the electromagnetic spectrum used in
(i) radar and
(ii) eye surgery. Write their frequency range.
Which is the correct ascending order of wavelengths?
How do the wavelengths and frequencies of microwaves compare with those of radio waves?
Which set lists uses of ultraviolet rays?
