# The Physics Alphabet

 Lower case letters Upper case Letters Greek Letters * and their names Equation Abbreviation for a Physical Quantity Unit symbol S.I. Prefix and its value NB it always precedes a unit symbol a A a A alpha A = area A = nucleon number (atomic mass) a = acceleration a = Wein constant a = alpha particle a = atto x 10-18 b B b B beta B = magnetic flux density b = beta particle B = bell (sound intensity) Bq = becquerel (activity) c C c C chi C = capacitance c = speed of light  c = specific heat capacity oC = degree Celsius (temperature) c = centi x 10-2 d D d D delta d = diameter d = distance D = distance from screen to fringe pattern D = absorbed dose D = change in d = little change in D = dioptre (power of a lens) dB = decibel (sound intensity) d = deci da = deca (or deka) x 10-1 x 101 e E e E epsilon e = charge on an electron E = energy Ek = kinetic energy E = electric field strength E = Young's Modulus e = emf e = tensile strain eo = permittivity of free space eV = electron volt (energy) E = exa x 1018 f F f F phi F = force f = frequency f = focal length fe = focal length of eyepiece lens fo = focal length of objective lens F = flux f = work function F = farad (capacitance) f = femto x 10-15 g G g G gamma g = gravitational field strength g = acceleration due to gravity G = gravitational constant G = conductance g = gamma ray Gy = gray (absorbed dose) G = giga x 109 h H h H eta h = height h = Planck constant H = dose equivalent H = hubble constant h = coefficient of viscosity H = henry (inductance) Hz = hertz (frequency) h = hecto x 102 I I I I iota I = current I0 = peak current I = sound intensity I = moment of inertia Care! Always 'top' and 'tail' I so that it can be differentiated from 1 or l j J j J theta J = current density J = moment of inertia J = angle J = joule (energy) k K k K kappa k = Boltzmann constant k = spring constant K = kelvin (absolute temperature) kg = kilogram (mass) k = kilo x 103 l L l L lamda l = length l = specific latent heat l = wavelength l = decay constant L = self inductance L = angular momentum ln = natural log of log = log base 10 of l = litre ( = 1000cm3) - volume measurement m M m M mu m = mass M = magnification m = permeability m = coefficient of friction m = metre (length) m2 = metre squared (area) m3 = metre cubed (volume) M = mega m = milli m = micro x 106 x 10-3 x 10-6 n N n N nu N = number NO = original number NA = Avogadro constant N = number of turns of wire n = number of moles n= order of diffraction n = number of charge carriers per unit volume n = refractive index N = newton (force or weight) n = nano x 10-9 o O o O omicron NOT used for anything. it would too easily be confused with the number zero p P p P pi P = power p = pressure p = momentum p = 3.14 Pa = pascal (pressure) p = pico P = peta x 10-12 x 1015 q Q Q = charge Q = heat energy Q = quality factor r R r R rho r = radius R = resistance R = molar gas constant R = reacrion force r = density r = resistivity rad = radian s S s S sigma s = displacement (vector version of distance) s = slit width s = conductivity s = tensile stress s = Stefan constant S = sum of s = second (time) Sv = sievert (dose equivalent) S = siemens (conductance) t T t T tau t = time T = temperature T = period of a waveform T1/2 = half life TE = effective half life TB = bilogical half life TP = physical half life T = tesla (magnetic flux density) T = tera x 1012 u U u U upsilon u = initial velocity u = image distance U = U-value U = internal heat of a system u = atomic mass unit (mass at atomic levels) v V v = velocity v = final velocity (when used in conjunction with 'u') v = image distance V = volume V = potential difference V0 = peak voltage V = volt (electric potential) w W w W omega W = work done w = angular velocity w = width of a fringe W = ohm (electrical resistance) W = watt (power) Wb =weber (magnetic flux) x X x X zeta x = width X = reactance y Y y Y xi y = height z Z z Z zeta z = depth Z = proton number (atomic number) The Greek letters are not in the order of the Greek alphabet but put next to their equivalent letter so that you can find them easily using the 'symbol' font in 'MSWord'' NOTE HOW IMPORTANT THE CASE OF THE LETTER IS - LEARN ACCEPTED SYMBOLS CAREFULLY!!! NB A level candidates are required to:  (a) define symbols used in an equation and  (b) the conditions under which the equations apply !!!

LOJ Nov 1999