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प्रश्न
Answer briefly.
Give two uses of radio waves.
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उत्तर
- Radio waves are used for wireless communication purposes.
- They are used for radio broadcasting and transmission of TV signals.
- Cellular phones use radio waves to transmit voice communication in the ultra-high frequency (UHF) band.
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संबंधित प्रश्न
Name the phenomenon which shows the quantum nature of electromagnetic radiation.
Name the high energetic invisible electromagnetic waves which help in the study of the structure of crystals
Name the electromagnetic radiations used for (a) water purification, and (b) eye surgery.
What do you understand by the statement, "Electromagnetic waves transport momentum"?
Name the subjective property of light related to its wavelength.
Which radiation is used for satellite communication?
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)X-rays,
State the approximate range of wavelength associated with visible light.
State the approximate range of wavelength associated with infrared rays.
Name two sources, each of infrared radiations and ultraviolet radiations.
An electromagnetic wave has a frequency of 500 MHz and a wavelength of 60 cm Calculate the velocity of the wave.
How are X-rays produced?
In a Coolidge tube, electrons strike the target and stop inside it. Does the target get more and more negatively charged as time passes?
Is it possible that in a Coolidge tube characteristic Lα X-rays are emitted but not Kα X-rays?
Can Lα X-ray of one material have shorter wavelength than Kα X-ray of another?
Can a hydrogen atom emit characteristic X-rays?
Why is exposure to X-rays injurious to health but not exposure to visible light, when both are electromagnetic waves?
Consider a photon of a continuous X-ray coming from a Coolidge tube. Its energy comes from
The energy of a photon of a characteristic X-ray from a Coolidge tube comes from
If the potential difference applied to the tube is doubled and the separation between the filament and the target is also doubled, the cutoff wavelength
Moseley's Law for characteristic X-ray is √v = a(Z − b). Here,
50% of the X-ray coming from a Coolidge tube is able to pass through a 0.1 mm thick aluminium foil. The potential difference between the target and the filament is increased. The thickness of the aluminium foil that will allow 50% of the X-ray to pass through will be
For a given material, the energy and wavelength of characteristic X-rays satisfy
(a) E(Kα) > E(Kβ) > E(Kγ)
(b) E(Mα) > E(Lα) > E(Kα)
(c) λ(Kα) > λ(Kβ) > λ(Kγ)
(d) λ(Mα) > λ(Lα) > λ(Kα).
Find the energy, the frequency and the momentum of an X-ray photon of wavelength 0.10 nm.
(Use Planck constant h = 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
What potential difference should be applied across an X-ray tube to get X-ray of wavelength not less than 0.10 nm? What is the maximum energy of a photon of this X-ray in joule?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
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.)
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- Calculate the speed of the wave.
- Name the medium through which it is traveling.
Name three radiations and their wavelength range which are invisible and beyond the violet end of the visible spectrum.
Identify the part of the electromagnetic spectrum used in
(i) radar and
(ii) eye surgery. Write their frequency range.
Name the radiations used for the detection of fracture in bones.
State two uses of infrared radiations.
Choose the correct option.
Earth’s atmosphere is richest in
Answer briefly.
Give two uses of ultraviolet rays.
An e.m. wave exerts pressure on the surface on which it is incident. Justify.
A radio can tune to any station in the 7.5 mHz to 12 MHz band. What is corresponding wave length band.
Identify the electromagnetic wave whose wavelength range is from about 10-12 m to about 10-8 m. Write one use of this.
Identify the electromagnetic wave whose wavelength range is from about 10-3 m to about 10-1 m. Write one use of this.
Choose the correct option related to wavelengths (λ) of different parts of the electromagnetic spectrum.
