Advertisements
Advertisements
प्रश्न
The terminology of different parts of the electromagnetic spectrum is given in the text. Use the formula E = hv (for energy of a quantum of radiation: photon) and obtain the photon energy in units of eV for different parts of the electromagnetic spectrum. In what way are the different scales of photon energies that you obtain related to the sources of electromagnetic radiation?
Advertisements
उत्तर
Energy of a photon is given as:
`"E" = "hv" = ("hc")/lambda`
Where,
h = Planck’s constant = 6.6 × 10−34 Js
c = Speed of light = 3 × 108 m/s
λ = Wavelength of radiation
∴ E = `(6.6 xx 10^-34 xx 3 xx 10^8)/lambda`
= `(19.8 xx 10^-26)/lambda` J
= `(19.8 xx 10^-26)/(lambda xx 1.6xx10^-19)` J
= `(12.375 xx 10^-7)/lambda "eV"`
The given table lists the photon energies for different parts of an electromagnetic spectrum for different λ.
| λ (m) | 103 | 1 | 10−3 | 10−6 | 10−8 | 10−10 | 10−12 |
| E (eV) | 12.375 × 10−10 | 12.375 × 10−7 | 12.375 × 10−4 | 12.375 × 10−1 | 12.375 × 101 | 12.375 × 103 | 12.375 × 105 |
The photon energies for the different parts of the spectrum of a source indicate the spacing of the relevant energy levels of the source.
संबंधित प्रश्न
A radio can tune in to any station in the 7.5 MHz to 12 MHz band. What is the corresponding wavelength band?
Give a reason for the following:
It is necessary to use satellites for long-distance TV transmission. Why?
A wave has wavelength 50 Å.
- Name the wave.
- State its speed in vacuum.
- State its one use.
Arrange the following radiations in the order of their increasing wavelength:
X-rays, infrared rays, ratio waves, gamma ray and microwaves.
Name the region beyond the red end of the spectrum.
Name two sources, each of infrared radiations and ultraviolet radiations.
Why is exposure to X-rays injurious to health but not exposure to visible light, when both are electromagnetic waves?
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.)
The wavelength of Kα X-ray of tungsten is 21.3 pm. It takes 11.3 keV to knock out an electron from the L shell of a tungsten atom. What should be the minimum accelerating voltage across an X-ray tube having tungsten target which allows production of Kα X-ray?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
The electron beam in a colour TV is accelerated through 32 kV and then strikes the screen. What is the wavelength of the most energetic X-ray photon?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Name three radiations and their wavelength range which are invisible and beyond the violet end of the visible spectrum.
Arrange the following electromagnetic waves in increasing order of their frequencies (i.e. begin with the lowest frequency):
Visible light, y rays, X rays, microwaves, radio waves, infrared radiations, and ultraviolet radiation.
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
Give one use of electromagnetic radiation in Ultraviolet radiation.
Choose the correct option.
The EM wave emitted by the Sun and responsible for heating the Earth’s atmosphere due to greenhouse effect is
X-rays, gamma rays and microwaves travelling in a vacuum have ______.
The ozone layer absorbs
SONAR emits which of the following waves?
What happens when an electron collides with a positron?
Name the electromagnetic radiation that has been used in obtaining the image below.
