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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
To which part of the electromagnetic spectrum does a wave of frequency 5 × 1011 Hz belong?
A radio can tune in to any station in the 7.5 MHz to 12 MHz band. What is the corresponding wavelength band?
A wave has wavelength 50 Å.
- Name the wave.
- State its speed in vacuum.
- State its one use.
What is the range of the wavelength of the following electromagnetic waves?
(a) Ultraviolet
Name the region beyond the red end of the spectrum.
What do you understand by the invisible spectrum?
State the approximate range of wavelength associated with the ultraviolet rays.
State the approximate range of wavelength associated with infrared rays.
Name two electromagnetic waves of frequency smaller than that of violet light. State one use of each.
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.
X-ray and visible light travel at the same speed in vacuum. Do they travel at the same speed in glass?
The X-ray beam emerging from an X-ray tube
The X-ray coming from a Coolidge tube has a cutoff wavelength of 80 pm. Find the kinetic energy of the electrons hitting the target.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
The Kβ X-ray of argon has a wavelength of 0.36 nm. The minimum energy needed to ionize an argon atom is 16 eV. Find the energy needed to knock out an electron from the K shell of an argon atom.
The Kα X-rays of aluminium (Z = 13) and zinc (Z = 30) have wavelengths 887 pm and 146 pm respectively. Use Moseley's law √v = a(Z − b) to find the wavelengths of the Kα X-ray of iron (Z = 26).
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
The Kα and Kβ X-rays of molybdenum have wavelengths 0.71 A and 0.63 A respectively. Find the wavelength of Lα X-ray of molybdenum.
The Kα and Kβ X-rays of molybdenum have wavelengths 0.71 A and 0.63 A respectively. Find the wavelength of Lα X-ray of molybdenum.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Suppose a monochromatic X-ray beam of wavelength 100 pm is sent through a Young's double slit and the interference pattern is observed on a photographic plate placed 40 cm away from the slit. What should be the separation between the slits so that the successive maxima on the screen are separated by a distance of 0.1 mm?
Two waves A and B have wavelength 0.01 Å and 9000 Å respectively.
Name the two waves. compare the speeds of these waves when they travel in vacuum.
Name the radiation which can be detected by thermopile.
Identify the part of the electromagnetic spectrum used in (i) radar and (ii) eye surgery. Write their frequency range.
Name the radiation of the electromagnetic spectrum which is used for the following:
To photograph internal parts of the human body and Give the frequency range
How will you investigate the existence of the radiation beyond the red and violet extremes of the spectrum?
Name two sources of ultraviolet radiation.
Give one use of electromagnetic radiation in Microwaves.
Name the radiations used for the detection of fracture in bones.
Answer briefly.
Why high-frequency carrier waves are used for the transmission of audio signals?
If the Earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
Given below in the left column are different modes of communication using the kinds of waves given in the right column.
| A. | Optical Fibre Communication |
P. | Ultrasound |
| B. | Radar | Q. | Infrared Light |
| C. | Sonar | R. | Microwaves |
| D. | Mobile Phones | S. | Radio Waves |
From the options given below, find the most appropriate match between entries in the left and the right column.
Give any two uses of infrared waves.
Identify the electromagnetic wave whose wavelength range is from about 10-12 m to about 10-8 m. Write one use of this.
Choose the correct option related to wavelengths (λ) of different parts of the electromagnetic spectrum.
Identify the electromagnetic radiation and write its wavelength range, which is used to kill germs in water purified. Name the two sources of these radiations.
Identify the part of the electromagnetic spectrum which:
- produces the heating effect.
- is absorbed by the ozone layer in the atmosphere.
- is used for studying crystal structure.
Write any one method of the production of each of the above radiations.
