Numerical Constants
Answers to RF Cafe Quiz #15 
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Return to RF Cafe Quiz #15
1. To which constant is 6.022*10^{23}/ mol assigned?
b) Avogadro's
constant
Avogadro's number is
the number of entities of a substance to make a mole. Avogadro's number is formally defined to be the number of
carbon12 atoms in 12 grams of unbound carbon12 in its restenergy electronic state. So, there are 6.022*10^{23}
carbon12 atoms in a gram of carbon12.
2. To which constant is 2.718 assigned?
a) base of natural logarithms
e^{1} = 2.718281828... The
definition is based on the fact
that the area of the region under the curve of a hyperbola (y=1/x) to the xaxis, between 1 and e, equals 1. That
gives the relationship in calculus where ln(e)=∫1/x*dx,
between x=1 and x=e
3. To which constant is
9,192,631,770
assigned?
b) oscillations of a cesium133 atom in exactly one second
The cesium atom's natural
frequency was formally recognized as the new
international unit of time in 1967: the second was defined as exactly 9,192,631,770 oscillations or cycles of
the cesium atom's resonant frequency.
4. To which constant is 1.616*10^{35} m
assigned?
a) Planck length
The
Planck length is often defined as the shortest possible length, but what it really means if the shortest
possible measurable length. This is because quantum effects significantly distort the measurement of distances
smaller than the Planck length.
5. To which constant is 9.11*10^{28} g
assigned?
c) electron rest mass
I'll let Jorge, of the
Journal of Theoretics
explain it.
6. To which constant is 9.81 m/s² assigned?
c) acceleration of
gravity near Earth's surface
To be more exact, it is the
acceleration of gravity at the
latitude of the Royal Observatory in the U.K.. Due to centrifugal force created by the Earth's rotation about its
axis, the measured force is greater near the poles than near the equator.
7. To which constant is
8.854*10^{12}
F/m assigned?
c) permittivity of free space
This is often written as ε_{0}. The
permittivity of free space (ε_{0}) is related to the speed of light and the permeability of free space (μ_{0})
by the following familiar equation 1/c = √(ε_{0*}μ_{0})
8. To which constant is 2.998*10^{8} m/s assigned to?
d) speed of
light in a vacuum
The speed of light
in vacuum is defined to be exactly 299,792,458 meters per second.
9. To which constant is
1.3807*10^{23} J/K assigned?
a) Boltzmann's constant
The Boltzmann
constant (k) relates energy and temperature at the particle level. Numerically, it is equal to the gas constant
(R) divided by the Avogadro constant (N_{a}), and it appears in equations like for noise in a given
bandwidth (kTB).
10. To which constant is 1.257*10^{6} H/m assigned?
d)
permeability of free space This is often written as μ_{0}. The permeability of free space (μ_{0})
is related to the speed of light and the permittivity of free space (ε_{0}) by the following familiar
equation 1/c = √(ε_{0*}μ_{0}) 






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