VOCABULARY
1. Choose the correct words from the brackets and complete the following
(1) (right, world, starve nothing. ungrateful free)
Pa says it would be
to leave it to
Doc Wilson said. "That's
Xalam
in the
comes quite
The bon
right and his daddy's right."
Answers
Explanation:
a
(
Z
−
b
)
,
ν=a(Z−b),
which gives
λ
=
c
ν
=
c
a
2
(
Z
−
b
)
2
.
λ=cν=ca2(Z−b)2.
Thus, the wavelength of emitted X-rays decreases with increase in
Z
Z. The cut-off wavelength of continuous X-rays corresponds to maximum energy of electron in X-ray tube. It is given by
h
c
/
λ
=
e
V
,
hc/λ=eV,
where
V
V is the accelerating potential. The intensity of X-rays depends on the number of electrons striking the target per second, which, in turn, depends on the electrical power given to the X-ray tube as energy of each electron is
e
V
eV.
Questions on Moseley's Law
Question: If 178.5 pm is the wavelength of X-ray line of copper (atomic number 29) and 71 pm is the wavelength of the X-ray line of molybdenum (atomic number 42) then the value of a and b in Moseley's equation are
A.
a
=
7
×
10
7
H
z
1
/
2
a=7×107Hz1/2, b=1.0
B.
a
=
5
×
10
7
H
z
1
/
2
a=5×107Hz1/2, b=7.4
C.
a
=
5
×
10
7
H
z
1
/
2
a=5×107Hz1/2, b=1.4
D.
a
=
7
×
10
7
H
z
1
/
2
a=7×107Hz1/2, b=7.4
Select and click to check answer
Question: Moseley's Law for characteristic X-rays is
√
ν
=
a
(
Z
−
b
)
ν=a(Z−b). In this formula
A. both a and b are independent on the material.
B. a is independent but b depends on the material.
C. b is independent but a depends on the material.
D. both a and b depend on the material.
Select and click to check answer
Related Topic
Characteristic and Continuous X-rays | Problems | IIT JEE
References and External Links
Z
−
b
)
2
.
λ=cν=ca2(Z−b)2.
Thus, the wavelength of emitted X-rays decreases with increase in
Z
Z. The cut-off wavelength of continuous X-rays corresponds to maximum energy of electron in X-ray tube. It is given by
h
c
/
λ
=
e
V
,
hc/λ=eV,
where
V
V is the accelerating potential. The intensity of X-rays depends on the number of electrons striking the target per second, which, in turn, depends on the electrical power given to the X-ray tube as energy of each electron is
e
V
eV.
Questions on Moseley's Law
Question: If 178.5 pm is the wavelength of X-ray line of copper (atomic number 29) and 71 pm is the wavelength of the X-ray line of molybdenum (atomic number 42) then the value of a and b in Moseley's equation are
A.
a
=
7
×
10
7
H
z
1
/
2
a=7×107Hz1/2, b=1.0
B.
a
=
5
×
10
7
H
z
1
/
2
a=5×107Hz1/2, b=7.4
C.
a
=
5
×
10
7
H
z
1
/
2
a=5×107Hz1/2, b=1.4
D.
a
=
7
×
10
7
H
z
1
/
2
a=7×107Hz1/2, b=7.4
Select and click to check answer
Question: Moseley's Law for characteristic X-rays is
√
ν
=
a
(
Z
−
b
)
ν=a(Z−b). In this formula
A. both a and b are independent on the material.
B. a is independent but b depends on the material.
C. b is independent but a depends on the material.
D. both a and b depend on the material.
Select and click to check answer
Related Topic
Characteristic and Continuous X-rays | Problems | IIT JEE
References and External Links
Concepts of Physics Part 2 by HC Verma (Link to Amazon)
IIT JEE Physics by Jitender Singh and Shraddhesh Chaturvedi
X-ray Fluorescence and Moseley’s Law (pdf article on X-rays, Moseley's Law and Moseley's Experiments)
The Physical (in)significance of Moseley's Screening Parameters, (journal article in pdf by K Razi Naqvi)
One hundred years of Moseley’s law: An undergraduate experiment with relativistic effects (pdf)At the present time, the widespread use of masks everywhere is not supported by high-quality scientific evidence, and there are fabric
If a,b,c,d are in G.P., show that (b-c)^2+(c-a)^2+(d-b)^2=(a-d)^2If a,b,c,d are in G.P., show that (b-c)^2+(c-a)^2+(d-b)^2=(a-d)^2logo image
Molecular Orbital Theory
Examples of
Multiple Choice Questions
1.
Which statement is false? A sigma molecular orbital
(a) may result from overlap of p atomic orbitals perpendicular to the molecular axis (side-on).
(b) may result from overlap of p atomic orbitals along the molecular axis (head-on).
(c) may result from overlap of two s atomic orbitals.
(d) may result from overlap of one s and one p atomic orbitals.
(e should encourage the use of non-medical, the widespread use of masks everywhere is not supported by high-quality scientific evidence, and there are fabric