Advertisements
Advertisements
प्रश्न
Why are infra-red waves often called heat waves? Explain.
Why are infrared waves often called heat waves? Given their one application.
Advertisements
उत्तर
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
संबंधित प्रश्न
What is the range of the wavelength of the following electromagnetic waves?
(a) Micro waves .
For harder X-rays,
(a) the wavelength is higher
(b) the intensity is higher
(c) the frequency is higher
(d) the photon energy is higher.
Find the cutoff wavelength for the continuous X-rays coming from an X-ray tube operating at 30 kV.
(Use Planck constant h = 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
A free atom of iron emits Kα X-rays of energy 6.4 keV. Calculate the recoil kinetic energy of the atom. Mass of an iron atom = 9.3 × 10−26 kg.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Answer briefly.
Why are microwaves used in radar?
If the Earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
SONAR emits which of the following waves?
In uranium (Z = 92) the K absorption edge is 0.107 Å and the Kα line is 0.126 Å, and the wavelength of the L absorption edge is ______.
Assertion (A): Ultraviolet radiations is scattered more as compared to the microwave radiations.
Reason (R): Wavelength of ultraviolet radiation is more than the wavelength of microwave radiation.
Which devices commonly produce microwaves?
