Advertisements
Advertisements
Question
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.)
Advertisements
Solution
Given:
Voltage of the X-ray tube, V = 30 kV
Cutoff wavelength for continuous X-rays (λ) is given by
`λ = (hc)/(eV)`
Here ,
h = Planck's constant
V = Voltage of the X-ray tube
c = Speed of light
`therefore lambda = (1242 "eV"-"nm")/(e xx 30 xx 10^3)`
⇒ `lambda = 414 xx 10^-4 "nm" = 41.4 "pm"`
APPEARS IN
RELATED QUESTIONS
If the earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
Name two sources, each of infrared radiations and ultraviolet radiations.
Name three properties of ultraviolet radiations which are similar to visible light.
How are X-rays produced?
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 electric current in an X-ray tube (from the target to the filament) operating at 40 kV is 10 mA. Assume that on an average, 1% of the total kinetic energy of the electron hitting hte target are converted into X-rays.
(a) What is the total power emitted as X-rays and (b) how much heat is produced in the target every second?
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 Kα and Kβ X-rays of molybdenum have wavelengths 0.71 A and 0.63 A respectively. Find the wavelength of Lα X-ray of molybdenum.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
The wavelengths of Kα and Lα X-rays of a material are 21.3 pm and 141 pm respectively. Find the wavelength of Kβ X-ray of the material.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.
Identify the part of the electromagnetic spectrum used in
(i) radar and
(ii) eye surgery. Write their frequency range.
Answer briefly.
Why are microwaves used in radar?
If λv, λx and λm Am represents the wavelength of visible light, x-ray and microwaves respectively, then ______.
Why does microwave oven heats up a food item containing water molecules most efficiently?
Write two uses of the following radiation.
Gamma rays
Which is the correct ascending order of wavelengths?
Name the electromagnetic radiation whose frequency is 10 Hz.
Name one radiation having the wavelength longer than the wavelength of these radiations.
