# Formula Symbols - E

Written by Jerry Ratzlaff on . Posted in Nomenclature & Symbols for Engineering, Mathematics, and Science

## Formula Symbols - E

For other symbols see:  A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z

SymbolGreek SymbolDefinitionUSMetric
$$g$$ - earth (mean) $$ft\;/\;sec^2$$ $$m\;/\;s^2$$
$$e$$ - eccentricity in mm
$$Ec$$ - Eckert number dimensionless number dimensionless number
$$I$$ - effective line current $$A$$ $$A$$
$$V$$ - effective line voltage $$V$$ $$V$$
$$m*_n \;or\; m*_p$$ - effective mass - -
$$E \;or\; \xi$$ xi effectiveness - -
$$\eta$$ eta efficiency $$percent$$ $$percent$$
$$\Theta_e$$ Theta Einstein temperature - -
$$E$$ - elastic - -
$$\lambda$$ lambda elastic modulus $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$
$$PE \;or\; E_p$$ - elastic potential energy $$ft-lbf$$ $$J$$
$$S$$ - elastic section modulus of a steal beam $$in^2$$ $$mm^2$$
$$E$$ - elasticity $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$
$$El$$ - elasticity number dimensionless number dimensionless number
$$q$$ - electric charge $$Ah$$ $$C$$
$$F$$ - electric capacitance $$C \;/\; V$$ $$C \;/\; V$$
$$S$$ - electric conductance $$A \;/\; V$$ $$A \;/\; V$$
$$\rho_{ik}$$ rho electric conductivity tensor - -
$$I$$ - electric current - -
$$J \;,\; j$$ - electric current density - -
$$p$$ - electric dipole moment - -
$$D$$ - electric displacement - -
$$E$$ - electric field - -
$$\psi$$ psi electric flux - -
$$V \;or\; \phi$$ phi electric potential $$W \;/\; A$$ $$W \;/\; A$$
$$U_e$$ - electric potential energy $$ft-lbf$$ $$J$$
$$\Omega$$ Omega electric resistance $$V \;/\; A$$ $$V \;/\; A$$
$$X_c$$ - electric susceptibility - -
$$\sigma$$ sigma electrical conductivity - -
$$R_e$$ - electrical resistance $$\Omega$$ $$\Omega$$
$$\rho$$ rho electrical resistivity $$\Omega^{-in}$$ $$\Omega^{-cm}$$
$$e$$ - electron - -
$$E_{ea}$$ - electron affinity - -
$$\frac {m_c}{m_{\alpha}}$$   electron-$$\alpha$$  particle mass ratio - -
$$w_{ce}$$ - electron cyclotron circular frequency - -
$$\frac {m_e}{m_d}$$ - electron-deuteron mass ratio - -
$$D_e$$ - electron diffusion coefficient - -
$$m_c$$ - electron mass - -
$$M \left( e \right) \;or\; M_e$$ - electron molar mass - -
$$\frac {m_c}{m_{\mu}}$$ mu electron-muon mass ratio - -
$$n_c$$ - electron number density - -
$$w_{pe}$$ - electron plasma circular frequency - -
$$\frac {m_c}{m_p}$$   electron-proton mass ratio - -
$$\frac {-e}{m_e}$$   electron specific charge - -
$$T_e$$ - electron temperature - -
$$e$$ - electronic charge - -
$$u \;or\; w$$ - electromagnetic energy density - -
$$E \;or\; \varepsilon$$ varepsilon electromotive force (EMF) - -
$$F_e$$ - electrostatic force - -
$$dl \;or\; ds$$ - element of path - -
$$e \;or\; \frac {e}{h}$$ - elementary change $$^\circ F$$ $$C$$
$$y$$ - elevation $$ft$$ $$m$$
$$y_i$$ - elevation at inlet $$ft$$ $$m$$
$$y_o$$  - elevation at outlet $$ft$$ $$m$$
$$\Delta y$$ Delta elevation differential $$ft$$ $$m$$
$$\epsilon$$ epsilon emissivity - -
$$E$$ - emissive power $$Btu \;/\; hr-ft^2$$ $$W \;/\; m^2$$
$$\gamma$$ gamma empirical constant $$1\;/\; F$$ $$1\;/\;C$$
$$\epsilon$$ epsilon empirical loss coefficient dimensionless number dimensionless number
$$r$$ - empirical rate - -
$$E \;or\; W$$ - energy $$ft-lbf$$ $$J$$
$$E \;or\; W$$ - energy $$Btu$$ $$kJ$$
$$E \;or\; W$$ - energy $$HP-hr$$ $$MJ$$
$$\Delta E$$ - energy differential $$ft-lbf$$ $$J$$
$$EER$$ - energy efficiency ratio $$Btu \;/\; W-hr$$ -
$$\epsilon$$ epsilon energy of particle - -
$$E_g$$ - energy gap - -
$$RPM$$ - engine speed rpm $$rad \;/\; s$$
$$H$$ - enthalpy $$ft-lbf$$ $$J$$
$$S$$ - entropy $$ft-lbf \;/\; ^\circ F$$ $$J\;/\;K$$
$$\Delta S$$ Delta entropy differential $$ft-lbf \;/\; ^\circ F$$ $$J\;/\;K$$
$$\phi$$ phi entropy function $$ft-lbf \;/\; ^\circ F$$ $$J\;/\;K$$
$$K$$ - equilibrium constant - -
$$EW$$ - equivalent weight $$lbm\;/\;lbmol$$ $$kg\;/\;kmol$$
$$n \;or\; n_n \;or\; n^{12}$$ - electron number density - -
$$\gamma$$ gamma empirical constant $$1 \;/\; F$$ $$1 \;/\; C$$
$$r$$ - empirical rate constant $$1 \;/\; hr$$ $$1 \;/\; s$$
$$Er$$ - Ericksen number dimensionless number dimensionless number
$$v_e$$ - escape velocity $$ft\;/\;sec$$ $$m\;/\;s$$
$$A_e \;or\; P_e$$ - Ettinghausen coefficient - -
$$Eu$$ - Euler number dimensionless number dimensionless number
$$J$$ - exchange integral  - -
$$Y$$ - expansion factor dimensionless number dimensionless number
$$e$$ - exponential constant - -