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प्रश्न
Answer briefly.
What is a carrier wave?
उत्तर
The high-frequency waves on which the signals to be transmitted are superimposed are called carrier waves.
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संबंधित प्रश्न
Identify the part of the electromagnetic spectrum which is suitable for radar system used in aircraft navigation.
State an additional use of the X-rays waves
Name the electromagnetic radiations used for (a) water purification, and (b) eye surgery.
Name the radiations of wavelength just longer than 8 × 10-7m.
Which part of electromagnetic spectrum is used in radar systems?
In a Coolidge tube, electrons strike the target and stop inside it. Does the target get more and more negatively charged as time passes?
Can X-rays be used for photoelectric effect?
Moseley's Law for characteristic X-ray is √v = a(Z − b). Here,
One of the following wavelengths is absent and the rest are present in the X-rays coming from a Coolidge tube. Which one is the absent wavelength?
50% of the X-rays coming from a Coolidge tube are able to pass through a 0.1 mm thick aluminium foil. If the potential difference between the target and the filament is increased, the fraction of the X-rays passing through the same foil will be
Visible light passing through a circular hole forms a diffraction disc of radius 0.1 mm on a screen. If an X-ray is passed through the same setup, the radius of the diffraction disc will be
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(a) the wavelength is higher
(b) the intensity is higher
(c) the frequency is higher
(d) the photon energy is higher.
The Kβ X-rays from certain elements are given below. Draw a Moseley-type plot of √v versus Z for Kβ radiation.
| Element | Ne | P | Ca | Mn | Zn | Br |
| Energy (keV) | 0.858 | 2.14 | 4.02 | 6.51 | 9.57 | 13.3 |
Name the scientist who discovered
X-rays
Name the scientist who discovered Infra-red waves
Name the part of the electromagnetic spectrum which is:
Suitable for radar systems used in aircraft navigation.
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Give one use of electromagnetic radiations in Infrared radiation.
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Earth’s atmosphere is richest in
Solve the numerical problem.
Calculate the frequency in MHz of a radio wave of wavelength 250 m. Remember that the speed of all EM waves in a vacuum is 3.0 × 108 m/s.
An e.m. wave exerts pressure on the surface on which it is incident. Justify.
The area to be covered for T.V telecast is doubled then the height of transmitting antenna (T.V tower) will have to be:-
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Electromagnetic waves with wavelength
- λ1 is suitable for radar systems used in aircraft navigation.
- λ2 is used to kill germs in water purifiers.
- λ3 is used to improve visibility in runways during fog and mist conditions.
Identify and name the part of the electromagnetic spectrum to which these radiations belong. Also arrange these wavelengths in ascending order of their magnitude.
Photons of an electromagnetic radiation has an energy 11 keV each. To which region of electromagnetic spectrum does it belong?
Name one radiation having the wavelength longer than the wavelength of these radiations.
