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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
What role dose infra-red radiation play in maintain the Earth’s warmth
What role dose infra-red radiation play in physical therapy?
Identify the part of the electromagnetic spectrum which is suitable for radar system used in aircraft navigation.
Identify the part of the electromagnetic spectrum which is:
produced by bombarding a metal target by high speed electrons.
If the earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
To which part of the electromagnetic spectrum does a wave of frequency 5 × 1011 Hz belong?
The small ozone layer on top of the stratosphere is crucial for human survival. Why?
(a) Give a list of at least five radiations, in order of their increasing frequencies, which make up the complete electromagnetic spectrum.
(b) Which of the radiation mentioned by you in part (a) has the highest penetrating power.
What is the range of the wavelength of the following electromagnetic waves?
(a) Infrared.
State the approximate range of wavelength associated with infrared rays.
Name three properties of ultraviolet radiations which are similar to visible light.
Which part of electromagnetic spectrum is used in radar systems?
The X-ray beam emerging from an X-ray tube
The figure shows the intensity-wavelength relations of X-rays coming from two different Coolidge tubes. The solid curve represents the relation for the tube A in which the potential difference between the target and the filament is VA and the atomic number of the target material is ZA. These quantities are VB and ZB for the other tube. Then,
X-ray incident on a material
(a) exerts a force on it
(b) transfers energy to it
(c) transfers momentum to it
(d) transfers impulse to it.
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 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.)
An X-ray tube operates at 40 kV. Suppose the electron converts 70% of its energy into a photon at each collision. Find the lowest there wavelengths emitted from the tube. Neglect the energy imparted to the atom with which the electron collides.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
The stopping potential in a photoelectric experiment is linearly related to the inverse of the wavelength (1/λ) of the light falling on the cathode. The potential difference applied across an X-ray tube is linearly related to the inverse of the cutoff wavelength (1/λ) of the X-ray emitted. Show that the slopes of the lines in the two cases are equal and find its value.
(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?
Name the scientist who discovered Infra-red waves
Name the part of the electromagnetic spectrum which is:
Produced by bombarding a metal target with high electrons.
Name two sources of ultraviolet radiation.
Give one use of electromagnetic radiation in Ultraviolet radiation.
What is the wavelength of the wave whose frequency is 1012 Hz? Name the electromagnetic wave.
Choose the correct option.
The EM wave emitted by the Sun and responsible for heating the Earth’s atmosphere due to greenhouse effect is
Answer briefly.
Why are microwaves used in radar?
Answer briefly.
Why light waves travel in a vacuum whereas sound waves cannot?
An e.m. wave exerts pressure on the surface on which it is incident. Justify.
Which of the following is a tool used for separating the different color wavelengths from each other?
A radio can tune to any station in the 7.5 mHz to 12 MHz band. What is corresponding wave length band.
What is time period of the light for which the eye is most sensitive?
Arrange the following electromagnetic radiation in the ascending order of their frequencies:
X-rays, microwaves, gamma rays, radio waves
In uranium (Z = 92) the K absorption edge is 0.107 Å and the Kα line is 0.126 Å, and the wavelength of the L absorption edge is ______.
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 radiation and write its wavelength range, which is used to kill germs in water purified. Name the two sources of these radiations.
Name the electromagnetic radiation whose frequency is 10 Hz.
Name one radiation having the wavelength longer than the wavelength of these radiations.
Name the electromagnetic radiation that has been used in obtaining the image below.
