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Note: Many answers contain passages quoted in whole or in part from the text.

**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
carbon-12 atoms in 12 grams of unbound carbon-12 in its rest-energy electronic state. So, there are 6.022*10

^{23}
carbon-12 atoms in a gram of carbon-12.

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 x-axis, 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 cesium-133 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})