Advertisements
Advertisements
प्रश्न
What are the ultraviolet rays?
उत्तर
- Ultraviolet rays can be produced by the mercury-vapor lamp, electric spark, and carbon arc lamp.
- They can also be obtained by striking electrical discharge in hydrogen and xenon gas tubes.
- The Sun is the most important natural source of ultraviolet rays, most of which is absorbed by the ozone layer in the Earth’s atmosphere.
APPEARS IN
संबंधित प्रश्न
Use the formula λm T= 0.29 cm K to obtain the characteristic temperature ranges for different parts of the electromagnetic spectrum. What do the numbers that you obtain tell you?
Arrange the following radiations in the order of their increasing wavelength:
X-rays, infrared rays, ratio waves, gamma ray and microwaves.
State the approximate range of wavelength associated with visible light.
Name the waves used for taking photographs in dark.
How are X-rays produced?
When a Coolidge tube is operated for some time it becomes hot. Where does the heat come from?
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
Mark the correct options.
(a) An atom with a vacancy has smaller energy that a neutral atom.
(b) K X-ray is emitted when a hole makes a jump from the K shell to some other shell.
(c) The wavelength of K X-ray is smaller than the wavelength of L X-ray of the same material.
(d) The wavelength of Kα X-ray is smaller than the wavelength of Kβ X-ray of the same material.
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.)
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.)
Name the scientist who discovered
X-rays
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.
| Gamma rays | D | C | Visible light | B | A |
The above table shows different parts of the electromagnetic spectrum.
(a) Identify the parts of the spectrum marked as A, B, C and D.
(b) Which of the radiations A or B has the higher frequency?
(c) State two properties which are common to all parts of the electromagnetic spectrum.
(d) Name one source of each of the radiation of electromagnetic spectrum.
(e) Name one detector for each of the radiation.
(f) Name one use of each of the radiation.
-
- Calculate the speed of the wave.
- Name the medium through which it is traveling.
Define the term "Intensity" in the photon picture of electromagnetic radiation.
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:
Radar and Give the frequency range.
Answer the following question.
Gamma rays and radio waves travel with the same velocity in free space. Distinguish between them in terms of their origin and the main application.
Answer briefly.
Why are microwaves used in radar?
Solve the numerical problem.
Calculate the wavelength in nm of an X-ray wave of frequency 2.0 × 1018 Hz.
X-rays, gamma rays and microwaves travelling in a vacuum have ______.
The area to be covered for T.V telecast is doubled then the height of transmitting antenna (T.V tower) will have to be:-
The magnetic field of a beam emerging from a filter facing a floodlight is given by B0 = 12 × 10–8 sin (1.20 × 107z – 3.60 × 1015t) T. What is the average intensity of the beam?
Arrange the following electromagnetic radiation in the ascending order of their frequencies:
X-rays, microwaves, gamma rays, radio waves
Which is the correct ascending order of wavelengths?
Which one of the following electromagnetic radiation has the least wavelength?
Choose the correct option related to wavelengths (λ) of different parts of the electromagnetic spectrum.
