Advertisements
Advertisements
Question
Characteristic X-rays may be used to identify the element from which they are being emitted. Can continuous X-rays be used for this purpose?
Advertisements
Solution
Characteristic X-rays are emitted due to the transitions of electrons among different shells. The wavelength of the X-rays emitted in these transitions have definite value for a particular element. But continuous X-rays are emitted due to the conversion of kinetic energy of an electron into photon, which varies from collision to collision and is independent of material. Hence, continuous X-rays provide no information about the element from which they are being emitted.
APPEARS IN
RELATED QUESTIONS
A radio can tune in to any station in the 7.5 MHz to 12 MHz band. What is the corresponding wavelength band?
(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.
Name the region beyond the red end of the spectrum.
State the approximate range of wavelength associated with visible light.
State the approximate range of wavelength associated with infrared rays.
Is it possible that in a Coolidge tube characteristic Lα X-rays are emitted but not Kα X-rays?
For harder X-rays,
(a) the wavelength is higher
(b) the intensity is higher
(c) the frequency is higher
(d) the photon energy is higher.
Name the scientist who discovered
X-rays
-
- Calculate the speed of the wave.
- Name the medium through which it is traveling.
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.
Answer briefly.
Why are microwaves used in radar?
Which of the following is a tool used for separating the different color wavelengths from each other?
For television broadcasting, the frequency employed is normally
Microwaves are electromagnetic waves with frequency in the range of.
The frequency of x-rays, y-rays and ultraviolet rays are respectively a, b and c. Then:-
Find the photon energy in units of ev for electromagnetic wave if waves length 40 m. Given h = 6.63 × 10–34 J.
Give any two uses of infrared waves.
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.
In an atom X, electrons absorb the energy from an external source. This energy “excites” the electrons from a lower-energy level to a higher-energy level around the nucleus of the atom. When electrons return to the ground state, they emit photons.
The figure below is the energy level diagram of atom X with three energy levels, E1 = 0.00eV, E2 = 1.78eV and E3 = 2.95eV. The ground state is considered 0 eV for reference. The transition of electrons takes place between levels E1 and E2.

- What wavelength of radiation is needed to excite the atom to energy level E2 from E1?
- Suppose the external source has a power of 100 W. What would be the rate of photon emission?
