Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
Given: λ = 250 m, c = 3 × 108 m/s
To find: Frequency (ν)
Formula: c = νλ
Calculation: From formula,
ν = `"c"/λ=(3xx10^8)/250` = 1.2 × 106 Hz = 1.2 MHz
The frequency of a radio wave is 1.2 MHz.
APPEARS IN
संबंधित प्रश्न
Identify the part of the electromagnetic spectrum which is suitable for radar system used in aircraft navigation.
Name the parts of the electromagnetic spectrum which is
used as a diagnostic tool in medicine.
Write in brief, how these waves can be produced.
A plane electromagnetic wave travels in the vacuum along the z-direction. What can you say about the directions of its electric and magnetic field vectors? If the frequency of the wave is 30 MHz, what is its wavelength?
Give one use of microwaves.
The wavelength of X-rays is 0.01 Å. Calculate its frequency. State the assumption made, if any.
Name of physical quantity which remains same for microwaves of wavelength 1 mm and UV radiations of 1600 Å in vacuum.
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?
Why is exposure to X-rays injurious to health but not exposure to visible light, when both are electromagnetic waves?
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.)
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.
State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.
Name three radiations and their wavelength range which are invisible and beyond the violet end of the visible spectrum.
Name the part of the electromagnetic spectrum which is:
Suitable for radar systems used in aircraft navigation.
Name the radiation of the electromagnetic spectrum which is used for the following:
For taking photographs of the sky during the night and foggy conditions . Give the frequency range
What are the ultraviolet rays?
Answer briefly.
What are radio waves?
Answer briefly.
Give two uses of radio waves.
If the Earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
The ozone layer absorbs
Find the photon energy in units of ev for electromagnetic wave if waves length 40 m. Given h = 6.63 × 10–34 J.
Radio waves of constant amplitude can be generated with.
If λv, λx and λm Am represents the wavelength of visible light, x-ray and microwaves respectively, then ______.
Electromagnetic waves with wavelength
- λ1 is used in satellite communication.
- λ2 is used to kill germs in water purifies.
- λ3 is used to detect leakage of oil in underground pipelines.
- λ4 is used to improve visibility in runways during fog and mist conditions.
- Identify and name the part of electromagnetic spectrum to which these radiations belong.
- Arrange these wavelengths in ascending order of their magnitude.
- Write one more application of each.
What happens to the intensity of light from a bulb if the distance from the bulb is doubled? As a laser beam travels across the length of a room, its intensity essentially remains constant. What geometrical characteristic of LASER beam is responsible for the constant intensity which is missing in the case of light from the bulb?
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.
The half-value thickness of an absorber is defined as the thickness that will reduce exponentially the intensity of a beam of particles by a factor of 2. The half-value thickness in (µm) for lead assuming X-ray beam of wavelength 20 pm, µ = 50 cm-1 for X-rays in lead at wavelength λ = 20 pm, is ______ µm.
Which one of the following electromagnetic radiation has the least wavelength?
