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Production of X-rays
Continuous and Characteristic X-rays
Soft and Hard X-rays
Moseley's law
Bragg’s law
Properties of X rays
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Showing posts with label Xrays. Show all posts
Showing posts with label Xrays. Show all posts
Wednesday, November 5, 2008
Sunday, July 13, 2008
X-rays - laws and theories
Moseley’s law
Moseley measured the frequencies of characteristic X-rays from large number of elements and plotted the square root of th frequency against its position number in the periodic table.
The observations can be mathematically expressed as
√(v) = a(Z-b)
v = the frequency of characteristic X-rays from the elements\
Z = atomic number
a, b are constants
Bragg’s law
2d sin θ = n λ
d = interplanar spacing of the crystal on which X-rays are incident
θ = is the incident angle at which X-rays are strongly reflected.
n = 1,2,3 …
λ = wave length of X-rays
Application of Bragg’s law:By using a monochromatic X-ray beam (having a single wave length) and noting the angles of strong reflection, the interplanar spacing d and several information about the structure of the solid can be obtained.
Moseley measured the frequencies of characteristic X-rays from large number of elements and plotted the square root of th frequency against its position number in the periodic table.
The observations can be mathematically expressed as
√(v) = a(Z-b)
v = the frequency of characteristic X-rays from the elements\
Z = atomic number
a, b are constants
Bragg’s law
2d sin θ = n λ
d = interplanar spacing of the crystal on which X-rays are incident
θ = is the incident angle at which X-rays are strongly reflected.
n = 1,2,3 …
λ = wave length of X-rays
Application of Bragg’s law:By using a monochromatic X-ray beam (having a single wave length) and noting the angles of strong reflection, the interplanar spacing d and several information about the structure of the solid can be obtained.
Sunday, March 23, 2008
Concept Review Ch.44 X-Rays
Production of X-rays
When highly energetic electrons are made to strike a metal target, electromagnetic radiation comes out. A large part of this radiation has wavelength of the order 0.1 nm (appx 1 A) and is known as X-ray.
Continuous and Characteristic X-Rays
If the X-rasy coming from a coolidge tube are examined for wavelengths present, and the intensity of different wavelengths are measurea and plotted, we can observe that there is a minimum wavelength below which no X-ray is emitted.
The wavelength below which no X-rays are emitted is called the cut-off wavelength or the threshold wavelength.
From the plot it can also be observed that at certain sharply defined wavelengths, the intensity of X-rays is very large. These X-rays are called characteristic X-rays.
At other wavelengths the intensity varies gradually and these X-rays are called continuous X-rays.
K X-Rays
X-rays emitted due to electronic transition from a higher energy state to a vacancy created in the K shell are called K X-rays.
Soft and Hard X-Rays
The X-rays of low wave length are called hard X rays and X rays of large wave length are called soft X rays.
In terms of energy, harder means more energy in is each photon.
Moseley's law
Square root of frequency of X rays = a(Z-b)
√(v) = a(Z-b)
where Z = position number of element.
a and b are constants
Bragg’s law
2d sin θ = n λ
d = interplanar spacing of the crystal on which X-rays are incident
θ = is the incident angle at which X-rays are strongly reflected.
n = 1,2,3 …
λ = wave length of X-rays
Application of Bragg’s law:By using a monochromatic X-ray beam (having a single wave length) and noting the angles of strong reflection, the interplanar spacing d and several information about the structure of the solid can be obtained.
Properties of X rays
X rays are electromagnetic waves of short wave lengths.
So they have many properties common with light.
1. They travel in straight lines in vacuum at a speed equal to that of light.
2. They are diffracted by crystals according to Bragg's law.
3. x-rays do not contain charged particles. hence they are not deflected by electric or magnetic field.
4. They effect a photographic plate. The effect is stronger than light.
Properties which are different than light
1. When incident on certain materials barium platinocyanide, X rays cause fluorescence.
2. When passed through a gas, X rays ionize the molecules of the gas.
When highly energetic electrons are made to strike a metal target, electromagnetic radiation comes out. A large part of this radiation has wavelength of the order 0.1 nm (appx 1 A) and is known as X-ray.
Continuous and Characteristic X-Rays
If the X-rasy coming from a coolidge tube are examined for wavelengths present, and the intensity of different wavelengths are measurea and plotted, we can observe that there is a minimum wavelength below which no X-ray is emitted.
The wavelength below which no X-rays are emitted is called the cut-off wavelength or the threshold wavelength.
From the plot it can also be observed that at certain sharply defined wavelengths, the intensity of X-rays is very large. These X-rays are called characteristic X-rays.
At other wavelengths the intensity varies gradually and these X-rays are called continuous X-rays.
K X-Rays
X-rays emitted due to electronic transition from a higher energy state to a vacancy created in the K shell are called K X-rays.
Soft and Hard X-Rays
The X-rays of low wave length are called hard X rays and X rays of large wave length are called soft X rays.
In terms of energy, harder means more energy in is each photon.
Moseley's law
Square root of frequency of X rays = a(Z-b)
√(v) = a(Z-b)
where Z = position number of element.
a and b are constants
Bragg’s law
2d sin θ = n λ
d = interplanar spacing of the crystal on which X-rays are incident
θ = is the incident angle at which X-rays are strongly reflected.
n = 1,2,3 …
λ = wave length of X-rays
Application of Bragg’s law:By using a monochromatic X-ray beam (having a single wave length) and noting the angles of strong reflection, the interplanar spacing d and several information about the structure of the solid can be obtained.
Properties of X rays
X rays are electromagnetic waves of short wave lengths.
So they have many properties common with light.
1. They travel in straight lines in vacuum at a speed equal to that of light.
2. They are diffracted by crystals according to Bragg's law.
3. x-rays do not contain charged particles. hence they are not deflected by electric or magnetic field.
4. They effect a photographic plate. The effect is stronger than light.
Properties which are different than light
1. When incident on certain materials barium platinocyanide, X rays cause fluorescence.
2. When passed through a gas, X rays ionize the molecules of the gas.
Thursday, February 7, 2008
IIT JEE Physics Formula Revision 44. X-Rays
1. K = eV
where K = Kinetic energy of an electron when it hits the target
V = potential difference applied between the target and the filament
2. λ = hc/E
Where
λ = wave length of the X-ray
E = kinteic energy of the electron due to which the X-ray is emitted
3. λmin = hc/eV
λmin = cutoff wavelength below which no X-rays are emitted
V = potential difference applied between the target and the filament
4. Moseley's law
Square root of frequency of X rays = a(Z-b)
√(ν) = a(Z-b)
where
ν = frequency of X-rays
Z = position number of element.
a and b are constants
5. Bragg’s law
2d sin θ = n λ
d = interplanar spacing of the crystal on which X-rays are incident
θ = is the incident angle at which X-rays are strongly reflected.
n = 1,2,3 …
λ = wave length of X-rays
where K = Kinetic energy of an electron when it hits the target
V = potential difference applied between the target and the filament
2. λ = hc/E
Where
λ = wave length of the X-ray
E = kinteic energy of the electron due to which the X-ray is emitted
3. λmin = hc/eV
λmin = cutoff wavelength below which no X-rays are emitted
V = potential difference applied between the target and the filament
4. Moseley's law
Square root of frequency of X rays = a(Z-b)
√(ν) = a(Z-b)
where
ν = frequency of X-rays
Z = position number of element.
a and b are constants
5. Bragg’s law
2d sin θ = n λ
d = interplanar spacing of the crystal on which X-rays are incident
θ = is the incident angle at which X-rays are strongly reflected.
n = 1,2,3 …
λ = wave length of X-rays
Tuesday, October 23, 2007
Study guide H C Verma JEE Physics Ch. 44 X-Rays
JEE Syllabus
Characteristic and continuous X-rays, Moseley's law;
---------------------
sections of the chapter
44.1 Production of X-rays
44.2 Continuous and characteristic X-rays
44.3 Soft and Hard X-rays
44.4 Moseley's law
44.5 Bragg's law
44.6 Properties and uses of X-rays
-----------------------
Study Plan
Day 1
44.1 Production of X-rays
44.2 Continuous and characteristic X-rays
44.3 Soft and Hard X-rays
Worked out examples 1 to 3
Day 2
44.4 Moseley's law
44.5 Bragg's law
44.6 Properties and uses of X-rays
WOE 3 to 6
Day 3
Exercises 1 to 10
Day 4
Exercises 11 to 20
Day5
Exercises 21 t0 27
Day 6
Objectives I and II
Day 7
Questions for short answer
Concept review
Formula review
JEE question 2007 Paper I
STATEMENT-1
If the accelerating potential in an X-ray tube is increased, the wavelengths of the characteristic X-ray do not change.
because
STATEMENT-2
When an electron beam strikes the target in an X-ray tube, part of the kinetic energy is converted into X-ray energy.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True
Correct choice: B
----------------------------------------
JEE 2007 Paper II
Electrons with de-Broglie wavelength λ fall on the target in an X-ray tube. The cut-off wavelength of the emitted X-ray is
(A) λ-0 = 2mcλ^2/h
(B) λ-0 = 2h/mc
(C) λ-0 = 2m^2c^2λ^3/h^2
(D) λ-0 = λ
Correct Choice: A
Cut – off wavelength corresponds to applied accelerating potential (V)
λ cut-off = hc/eV
eV = (1/2)mv^2 = P^2/2m
and P = h/λ
eV = h^2/2mλ^2 =
λ cutoff = hc/(h^2/2mλ^2) = hc*2mλ^2/h^2 = 2mcλ^2/h
---------------------------
Characteristic and continuous X-rays, Moseley's law;
---------------------
sections of the chapter
44.1 Production of X-rays
44.2 Continuous and characteristic X-rays
44.3 Soft and Hard X-rays
44.4 Moseley's law
44.5 Bragg's law
44.6 Properties and uses of X-rays
-----------------------
Study Plan
Day 1
44.1 Production of X-rays
44.2 Continuous and characteristic X-rays
44.3 Soft and Hard X-rays
Worked out examples 1 to 3
Day 2
44.4 Moseley's law
44.5 Bragg's law
44.6 Properties and uses of X-rays
WOE 3 to 6
Day 3
Exercises 1 to 10
Day 4
Exercises 11 to 20
Day5
Exercises 21 t0 27
Day 6
Objectives I and II
Day 7
Questions for short answer
Concept review
Formula review
JEE question 2007 Paper I
STATEMENT-1
If the accelerating potential in an X-ray tube is increased, the wavelengths of the characteristic X-ray do not change.
because
STATEMENT-2
When an electron beam strikes the target in an X-ray tube, part of the kinetic energy is converted into X-ray energy.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True
Correct choice: B
----------------------------------------
JEE 2007 Paper II
Electrons with de-Broglie wavelength λ fall on the target in an X-ray tube. The cut-off wavelength of the emitted X-ray is
(A) λ-0 = 2mcλ^2/h
(B) λ-0 = 2h/mc
(C) λ-0 = 2m^2c^2λ^3/h^2
(D) λ-0 = λ
Correct Choice: A
Cut – off wavelength corresponds to applied accelerating potential (V)
λ cut-off = hc/eV
eV = (1/2)mv^2 = P^2/2m
and P = h/λ
eV = h^2/2mλ^2 =
λ cutoff = hc/(h^2/2mλ^2) = hc*2mλ^2/h^2 = 2mcλ^2/h
---------------------------
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