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प्रश्न
Why are microwaves considered suitable for radar systems used in aircraft navigation?
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उत्तर
Microwaves are considered suitable for radar systems used in aircraft navigation because they have a short wavelength range (10−3 m–0.3 m), which makes them suitable for long-distance communication.
संबंधित प्रश्न
Give a reason for the following:
It is necessary to use satellites for long-distance TV transmission. Why?
What is the range of the wavelength of the following electromagnetic waves?
(a) Gamma rays.
What is the range of the wavelength of the following electromagnetic waves?
(a) Infrared.
Name the region beyond the red end of the spectrum.
Give one use of microwaves.
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.)
The electric current in an X-ray tube (from the target to the filament) operating at 40 kV is 10 mA. Assume that on an average, 1% of the total kinetic energy of the electron hitting hte target are converted into X-rays.
(a) What is the total power emitted as X-rays and (b) how much heat is produced in the target every second?
Heat at the rate of 200 W is produced in an X-ray tube operating at 20 kV. Find the current in the circuit. Assume that only a small fraction of the kinetic energy of electrons is converted into X-rays.
When 40 kV is applied across an X-ray tube, X-ray is obtained with a maximum frequency of 9.7 × 1018 Hz. Calculate the value of Planck constant from these data.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Name two sources of ultraviolet radiation.
