The University of British Columbia - Department of Physics and Astronomy

Roman Characters Commonly Used in Physics

Symbols:     T_EX   |   Greek   |   Math

Web version by Jess H. Brewer

Italicized Characters Representing VARIABLES:

(Not all usages are shown. Most common are italicized)

A    an area; the vector potential.
a    acceleration; a general constant.
B    magnetic induction.
b    a general constant.
C    heat capacity.
c    speed of light; a general constant.
D    electric displacement.
d    differential operator; diameter; a distance.
${\cal E}$    energy; "electromotive force" (voltage).
E    energy; electric field.
e    2.71828$\cdots$ ; electron's charge.
F    force; a general function; free energy.
f    a fraction; a function as in f(x).
G    Newton's universal gravitational constant.
g    acceleration of gravity at Earth's surface.
${\cal H}$    Hamiltonian operator.
H    magnetic field; enthalpy.
h    Planck's constant; a height.
I    electric current.
i    $\sqrt{-1}$ ; an index (subscript); current.
$\hat{\imath}$    unit vector in the x direction.
J    spin angular momentum; electric current density.
j    a common integer index; current density.
$\hat{\jmath}$    unit vector in the y direction.
K    kinetic energy.
k    an integer index; a general constant.
$\hat{k}$    unit vector in the z direction.
L    angular momentum; length.
l    an integer index; a length.
M    magnetization; mass.
m    mass; an integer index.
N    a large number.
n    a small number.
${\cal O}$    "order of" symbol as in ${\cal O}(\alpha)$.
o    rarely used (looks like a zero).
P    probability; pressure; power.
p    momentum.
Q    electric charge; quality factor.
q    electric charge; "canonical coordinate".
R    radius; electrical resistance.
r    radius.
S    entropy; surface area.
s    a distance.
T    temperature.
t    time; thickness.
U    potential energy; internal energy.
u    an abstract variable; a velocity.
V    volume; potential.
v    velocity; an abstract variable.
W    work; weight; charged vector boson.
w    a small weight; a width.
X    an abstract function like X(x).
x    distance; any independent variable.
Y    an abstract function like Y(y).
y    distance; any dependent variable.
Z    atomic number; Z(z); neutral boson.
z    distance; any dependent variable.

Single-letter abbreviations for UNITS:

(Not all are shown.)

A    Amperes.
a    prefix atto- (x 10^-18).
C    Coulombs; degrees Celcius.
c    prefix centi- (x 10^-2).
d    prefix deci- (x 10^-1 or deca- (x 10).
E    prefix exa- (x 10¹⁸).
f    prefix femto- (x 10^-15).
G    Gauss; prefix giga- (x 10⁹).
p    prefix pico- (x 10^-12).
H    Henries.
J    Joules.
K    degrees Kelvin.
k    prefix kilo- (x 10³).
M    prefix mega- (x 10⁶).
m    metres; prefix milli- (x 10^-3).
N    Newtons.
n    prefix nano- (x 10^-9).
P    Pascals; prefix peta- (x 10¹⁵).
p    prefix pico- (x 10^-12).
s    seconds.
T    Tesla; prefix tera- (x 10¹²).
V    Volts.
W    Watts.