Please enable JavaScript.
Coggle requires JavaScript to display documents.
EEE1001 - Electromagnetism (Electromagnetism (\(C=\frac{\epsilon A}{w}\)…
EEE1001 - Electromagnetism
Electromagnetism
\(MMF = Ni\)
\(H=\frac{MMF}{L}\)
\(B=\mu H\)
\(\phi=BA\)
\(\psi = N\phi = Li\)
V = \(-\frac{\mathrm{d}\phi}{\mathrm{d}t}\)
\(S=\frac{L}{\mu A}=\frac{N^2}{L}\)
\(E=\frac{1}{2}Li^2\)
\(V=BLv\)
\(\)
\(\vec{F}=Q\vec{E} + Q\vec{v}\times\vec{B}\)
\(F_m=\frac{1}{2}\mu H^2A\) (?)
\(F_e=\frac{\epsilon}{2}E^2A\)
\(F_{x}=\frac{1}{2}i^2\frac{\mathrm{d}L}{\mathrm{d}x}\)
\(V_{att}(r)=\frac{e^2}{4\pi\epsilon r}\)
\(C=\frac{\epsilon A}{w}\)
\(E=\frac{1}{2}CV^2\)
\(Q=CV\)
\(C=\frac{\mathrm{d}Q}{\mathrm{d}V}\)
Materials
Equipartition of energy
(\(\frac{kT}{2}\)J per molecule per degree of freedom)
Vibrational DoF can be ignored for low-mass molecules
Linear N-atomic: 3 translational, 2 rotational, \(3N-5\) vibrational
Non-linear N-atomic: 3 translational, 2 rotational, \(3N-6\) vibrational
Atoms: 3 translational
\(\)
Mean free path
\(\lambda=\frac{1}{\pi d^2n_v}\) where \(n_v\) is the number density
Real gases
can be modeled by \(PV^3-(Pb+RT)V^2+aV-ab=0)\) where \(b\) is the volume occupied by 1 mole of gas (can be found using \(d\))
Saturated vapour pressure
is the vapour pressure when the rate of molecules leaving the liquid surface equals the rate of return: it is \(\propto T\)
Partial pressure
is the saturated vapour pressure with no other gas present
Total pressure
is the partial pressure \(+\) the air pressure
Boiling
occurs when the SVP \(>\) the exterior pressure at the liquid surface
Cohesion
is due to intermolecular forces within a liquid
Adhesion
is due to intermolecular forces between a liquid and a solid
The greater force determines whether a liquid wets a surface or forms droplets
\(\)
Surface tension force \(F=2\sigma l\) if considering
both
sides of the film
Capillary height \(h=\frac{2\sigma\cos{\theta}}{\rho gr}\)
The
critical point
is where liquid and gas have the same density: they can't be distinguished
The
triple point
is where solid, liquid and gas coexist in equilibrium
Surface tension \(\sigma=\frac{\Delta W}{\Delta A}\)
\(v_{rms}=\sqrt{\frac{3kT}{m}}\)
Semiconductors
\(P\propto e^{-\frac{E_g}{2kT}}\)
\(\)
In n-type doping, \(N_D \gg n_i\) hence \(n_n\simeq N_D\)
n-type and p-type doping will cancel one another out, leaving \(p\) or \(n\) equal to \(|N_A-N_D|\)
\(\)
In
p-type
doping, dopants with less electrons accept electrons from the valence band: \(N_A=[X]\)
In
n-type
doping, dopants with more electrons donate electrons to the conduction band: \(N_D=[X]\)
\(\)
Drift velocities due to an electric field \(E=-\frac{\mathrm{d}V}{\mathrm{d}x}\): \(v_e=-\mu_eE\) and \(v_h=\mu_hE\)
Semiconductor conductivity is the inverse of resistivity i.e. \(\sigma = \frac{1}{\rho}\)
If doping is uneven (i.e. \(n\) is a function of \(x\)), a diffusion current forms. Electrons move from high \(n\) to low \(n\).
This produces an E-field \(E_B\) (the
built in field
) with an associated drift current such that \(I_D=I_{E_B}\) (with no ext. field)
The
majority carrier diffusion current
is usually the only one considered
A pn junction is in
reverse bias
if the applied \(E\)-field is in the direction of \(E_B\) (i.e. \(V_J<0\)
\(I=\frac{V_s-\frac{E_g}{e}}{R}\)