Question
How are infrared waves produced? State their properties and uses.
✓
Answer
Production:
- All hot bodies are sources of infrared rays. About 60% of the solar radiations are infrared in nature.
- Thermocouples, thermopile and bolometers are used to detect infrared rays.
- When infrared rays are incident on any object, the object gets heated.
- These rays are strongly absorbed by glass.
- They can penetrate through thick columns of fog, mist and cloud cover.
- Used in remote sensing.
- Used in diagnosis of superficial tumours and varicose veins.
- Used to cure infantile paralysis and to treat sprains, dislocations and fractures.
- They are used in solar water heaters and solar cookers.
- Special infrared photographs of the body called thermograms, can reveal diseased organs because these parts radiate less heat than the healthy organs.
- Infrared binoculars and thermal imaging cameras are used in military applications for night vision.
- Used to keep green house warm.
- Used in remote controls of TV, VCR, etc.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The Earth is rotating with angular velocity $ω$ about its own axis. $R$ is the radius of the Earth. If $Rω^2 = 0.03386 \ m/s^2,$ calculate the weight of a body of mass $100$ gram at latitude $25^\circ . (g = 9.8 \ m/s^2)$
→$\hat{ i }$ and $\hat{ j }$ are unit vectors along $X -$ axis and $Y -$ axis respectively. What is the magnitude and direction of the vector $\hat{ i }+\hat{ j }$ and $\hat{ i }-\hat{ j }$ ? What are the components of a vector $\overrightarrow{ A }=2 \hat{ i }+ 3 \hat{ j }$ along the directions of $(\hat{ i }+\hat{ j })$ and $(\hat{ i }-\hat{ j }) ? \ (\text{NCERT})$
→Define gravitational force. Give its examples.
Obtain an expression for the time of flight of a projectile.
That are rectangular components of vectors? Explain their uses.
A $20 g$ bullet leaves a machine gun with a velocity of $200 \ m/s.$ If the mass of the gun is $20 \ kg,$ find its recoil velocity. If the gun fires $20$ bullets per second, what force is to be applied to the gun to prevent recoil?
→Derive the expression for the acceleration due to gravity on the surface of the Earth.
A girl stands 170 m away from a high wall and claps her hands at a steady rateso that each clap coincides with the echo of the one before.
a) If she makes 60 claps in 1 minute, what value should be the speed of sound in air?
b) Now, she moves to another location and finds that she should now make 45 claps in 1 minute to coincide with successive echoes. Calculate her distance for the new position from the wall.
a) If she makes 60 claps in 1 minute, what value should be the speed of sound in air?
b) Now, she moves to another location and finds that she should now make 45 claps in 1 minute to coincide with successive echoes. Calculate her distance for the new position from the wall.
Explain series combination of resistors.
From the following figure, determine the resultant of four forces $\overrightarrow{ A }_1, \overrightarrow{ A }_2, \overrightarrow{ A }_3, \overrightarrow{ A }_4$
→