উইকিপিডিয়া, মুক্ত বিশ্বকোষ থেকে
পদার্থবিজ্ঞানে , একটি ভৌত ধ্রুবক হল একটি ভৌত রাশির মান যা সার্বজনীন হিসেবে গৃহীত হয় এবং বিশ্বাস করা হয় যে এর মান সময়ের সাথে পরিবর্তিত হয় নাা।
Quantity
Symbol
Value1 (SI units)
Relative Standard Uncertainty
Bohr magneton
μ
B
=
e
ℏ
/
2
m
e
{\displaystyle \mu _{B}=e\hbar /2m_{e}}
927.400 949(80) × 10−26 J·T−1
8.6 × 10-8
conductance quantum
G
0
=
2
e
2
/
h
{\displaystyle G_{0}=2e^{2}/h\,}
7.748 091 733(26) × 10−5 S
3.3 × 10−9
Coulomb's constant
κ
=
1
/
4
π
ϵ
0
{\displaystyle \kappa =1/4\pi \epsilon _{0}\,}
8.987 742 438 × 109 N·m2 C−2
defined
Josephson constant
K
J
=
2
e
/
h
{\displaystyle K_{J}=2e/h\,}
483 597.879(41) × 109 Hz· V−1
8.5 × 10−8
magnetic flux quantum
ϕ
0
=
h
/
2
e
{\displaystyle \phi _{0}=h/2e\,}
2.067 833 72(18) × 10−15 Wb
8.5 × 10−8
nuclear magneton
μ
N
=
e
ℏ
/
2
m
p
{\displaystyle \mu _{N}=e\hbar /2m_{p}}
5.050 783 43(43) × 10−27 J·T−1
8.6 × 10−8
resistance quantum
R
0
=
h
/
2
e
2
{\displaystyle R_{0}=h/2e^{2}\,}
12 906.403 725(43) Ω
3.3 × 10−9
von Klitzing constant
R
K
=
h
/
e
2
{\displaystyle R_{K}=h/e^{2}\,}
25 812.807 449(86) Ω
3.3 × 10−9
Quantity Symbol Value1 (SI units) Relative Standard Uncertainty
Bohr radius
a
0
=
α
/
4
π
R
∞
{\displaystyle a_{0}=\alpha /4\pi R_{\infty }\,}
5.291 772 108 (18) × 10−11 m
3.3 × 10−9
Fermi coupling constant
G
F
/
(
ℏ
c
)
3
{\displaystyle G_{F}/(\hbar c)^{3}}
1.166 39(1) × 10−5 GeV−2
8.6 × 10−6
fine-structure constant
α
=
μ
0
e
2
c
/
(
2
h
)
=
e
2
/
(
4
π
ϵ
0
ℏ
c
)
{\displaystyle \alpha =\mu _{0}e^{2}c/(2h)=e^{2}/(4\pi \epsilon _{0}\hbar c)\,}
7.297 352 568(24) × 10−3
3.3 × 10−9
Hartree energy
E
h
=
2
R
∞
h
c
{\displaystyle E_{h}=2R_{\infty }hc\,}
4.359 744 17(75) × 10−18 J
1.7 × 10−7
quantum of circulation
h
/
2
m
e
{\displaystyle h/2m_{e}\,}
3.636 947 550(24) × 10−4 m2 s−1
6.7 × 10−9
Rydberg constant
R
∞
=
α
2
m
e
c
/
2
h
{\displaystyle R_{\infty }=\alpha ^{2}m_{e}c/2h\,}
10 973 731.568 525(73) m−1
6.6 × 10−12
Thomson cross section
(
8
π
/
3
)
r
e
2
{\displaystyle (8\pi /3)r_{e}^{2}}
0.665 245 873(13) × 10−28 m2
2.0 × 10−8
weak mixing angle
sin
2
θ
W
=
1
−
(
m
W
/
m
Z
)
2
{\displaystyle \sin ^{2}\theta _{W}=1-(m_{W}/m_{Z})^{2}\,}
0.222 15(76)
3.4 × 10−3
Quantity Symbol Value1 (SI units) Relative Standard Uncertainty
atomic mass constant (unified atomic mass unit)
m
u
=
1
u
{\displaystyle m_{u}=1\ u\,}
1.660 538 86(28) × 10−27 kg
1.7 × 10−7
Avogadro's number
N
A
,
L
{\displaystyle N_{A},L\,}
6.022 1415(10) × 1023
1.7 × 10−7
Boltzmann constant
k
=
R
/
N
A
{\displaystyle k=R/N_{A}\,}
1.380 6505(24) × 10−23 J·K−1
1.8 × 10−6
Faraday constant
F
=
N
A
e
{\displaystyle F=N_{A}e\,}
96 485.3383(83)C·mol−1
8.6 × 10−8
first radiation constant
c
1
=
2
π
h
c
2
{\displaystyle c_{1}=2\pi hc^{2}\,}
3.741 771 38(64) × 10−16 W·m2
1.7 × 10−7
for spectral radiance
c
1
L
{\displaystyle c_{1L}\,}
1.191 042 82(20) × 10−16 W · m2 sr−1
1.7 × 10−7
Loschmidt constant at
T
{\displaystyle T}
p
{\displaystyle p}
n
0
=
N
A
/
V
m
{\displaystyle n_{0}=N_{A}/V_{m}\,}
2.686 7773(47) × 1025 m−3
1.8 × 10−6
gas constant
R
{\displaystyle R\,}
8.314 472(15) J·K−1 ·mol−1
1.7 × 10−6
molar Planck constant
N
A
h
{\displaystyle N_{A}h\,}
3.990 312 716(27) × 10−10 J · s · mol−1
6.7 × 10−9
molar volume of an ideal gas
at
T
{\displaystyle T}
p
{\displaystyle p}
V
m
=
R
T
/
p
{\displaystyle V_{m}=RT/p\,}
22.710 981(40) × 10−3 m3 ·mol−1
1.7 × 10−6
at
T
{\displaystyle T}
p
{\displaystyle p}
22.413 996(39) × 10−3 m3 ·mol−1
1.7 × 10−6
Sackur-Tetrode constant at
T
{\displaystyle T}
p
{\displaystyle p}
S
0
/
R
=
5
2
{\displaystyle S_{0}/R={\frac {5}{2}}}
+
ln
[
(
2
π
m
u
k
T
/
h
2
)
3
/
2
k
T
/
p
]
{\displaystyle +\ln \left[(2\pi m_{u}kT/h^{2})^{3/2}kT/p\right]}
-1.151 7047(44)
3.8 × 10−6
at
T
{\displaystyle T}
p
{\displaystyle p}
-1.164 8677(44)
3.8 × 10−6
second radiation constant
c
2
=
h
c
/
k
{\displaystyle c_{2}=hc/k\,}
1.438 7752(25) × 10−2 m·K
1.7 × 10−6
Stefan-Boltzmann constant
σ
=
(
π
2
/
60
)
k
4
/
ℏ
3
c
2
{\displaystyle \sigma =(\pi ^{2}/60)k^{4}/\hbar ^{3}c^{2}}
5.670 400(40) × 10−8 W·m−2 ·K−4
7.0 × 10−6
Wien displacement law constant
b
=
(
h
c
/
k
)
/
{\displaystyle b=(hc/k)/\,}
2.897 7685(51) × 10−3 m · K
1.7 × 10−6
Quantity Symbol Value (SI units) Relative Standard Uncertainty
conventional value of Josephson constant 2
K
J
−
90
{\displaystyle K_{J-90}\,}
483 597.9 × 109 Hz · V−1
defined
conventional value of von Klitzing constant 3
R
K
−
90
{\displaystyle R_{K-90}\,}
25 812.807 Ω
defined
molar mass
constant
M
u
=
M
(
12
C
)
/
12
{\displaystyle M_{u}=M(\,^{12}{\mbox{C}})/12}
1 × 10−3 kg · mol−1
defined
of carbon-12
M
(
12
C
)
=
N
A
m
(
12
C
)
{\displaystyle M(\,^{12}{\mbox{C}})=N_{A}m(\,^{12}{\mbox{C}})}
12 × 10−3 kg · mol−1
defined
standard acceleration of gravity (gee , free fall on Earth)
g
n
{\displaystyle g_{n}\,\!}
9.806 65 m·s−2
defined
standard atmosphere
atm
{\displaystyle {\mbox{atm}}\,}
101 325 Pa
defined
1 The values are given in the so-called concise form ; the number in brackets is the standard uncertainty relative standard uncertainty 2 This is the value adopted internationally for realizing representations of the volt using the Josephson effect .3 This is the value adopted internationally for realizing representations of the ohm using the quantum Hall effect .
পদার্থবিজ্ঞানে, একটি ভৌত ধ্রুবক হল একটি ভৌত রাশির মান যা সার্বজনীন হিসেবে গৃহীত হয় এবং বিশ্বাস করা হয় যে এর মান সময়ের সাথে পরিবর্তিত হয় নাা।
![{\displaystyle +\ln \left[(2\pi m_{u}kT/h^{2})^{3/2}kT/p\right]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f620d502b24516f88ec1e1637e8a13ef534f127f)
