Advertisements
Advertisements
प्रश्न
Frequencies of Kα X-rays of different materials are measured. Which one of the graphs in the figure may represent the relation between the frequency v and the atomic number Z ?
Advertisements
उत्तर
Using Moseley's Law,
`sqrt(v) = a(Z - b)`,
where v = frequency of Kα X-ray
Z = atomic number
`therefore v = a^2(Z - b)^2`
⇒ `(Z - b)^2 = v/a^2`
This is the equation of a parabola with some intercept on the axis, representing atomic number (Z). Hence, curve d represent this relation correctly.
APPEARS IN
संबंधित प्रश्न
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?
A radio can tune in to any station in the 7.5 MHz to 12 MHz band. What is the corresponding wavelength band?
Optical and radio telescopes are built on the ground but X-ray astronomy is possible only from satellites orbiting the earth. Why?
The wavelengths for the light of red and blue colours are roughly 7.8 × `10^7` m and 4.8 × `10^7` m respectively.
(a) Which colour has the greater speed in vacuum?
(b) Which colour has the greater speed in glass?
What is the range of the wavelength of the following electromagnetic waves?
(a) Micro waves .
State the approximate range of wavelength associated with the ultraviolet rays.
State the approximate range of wavelength associated with infrared rays.
Visible light passing through a circular hole forms a diffraction disc of radius 0.1 mm on a screen. If an X-ray is passed through the same setup, the radius of the diffraction disc will be
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.)
Name the scientist who discovered Infra-red waves
Name the part of the electromagnetic spectrum which is:
Suitable for radar systems used in aircraft navigation.
Answer briefly.
Why are microwaves used in radar?
Answer briefly.
Why light waves travel in a vacuum whereas sound waves cannot?
What are the ultraviolet rays?
Which of the following is a tool used for separating the different color wavelengths from each other?
The frequency of e. m waves which is best suited .to observed of radius 3 × 10–4 his of the order of
What is time period of the light for which the eye is most sensitive?
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.
