Supplementary Notes for
Physics 2 Discussion
Tomoyuki Nakayama a.k.a Tom
I just started to make the notes so
don’t expect too much
Fundamentals of Electric & Magnetic
Field
Electric Field is produced by
charges.
Electric field due to point
charge q is given by:
E = (1/4πε)(q/r2)
(Coulomb’s law)
If you can choose a closed
surface on which E is
constant, you can use
E┴A = Qin/ε (Gauss’s Law)
Magnetic Field is produced
by moving charges or
currents.
Magnetic field due to a
moving charge or current
element is given by:
B = (μ/4π)(qvsinθ/r2)
= (μ/4π)(IΔLsinθ/r2)
(Biot-Savart Law)
If you can choose a closed
loop on which B is constant,
you can use
B║L = μIin (Ampere’s Law)
Application of Gauss’s Law & Ampere’s
Law
Electric field due to a
uniform charge
distribution along a
long, straight line.
Magnetic field due to
a steady current in a
long, straight wire.
RLC Series/Parallel AC Circuit
RLC in Series
I is common. (So we use I
as a reference.)
ΔV across R is in phase
w/ I & ΔVR = RI
ΔV across L is 90º ahead
of I & ΔVL = XLI.
ΔV across C is 90º
behind I & ΔVC = XCI.
RLC in Parallel
ΔV is common. (So we
use ΔV as a reference.)
I in R is in phase w/ ΔV &
IR = ΔV/R.
I in L is 90º behind ΔV &
IL = ΔV/XL.
I in C is 90º ahead of ΔV
& IC = ΔV/XC.
Impedance &Phase Angle of RLC
Series/Parallel AC Circuits
RLC in Series
Total voltage drop is
the vector sum of the
voltages across each
element.
RLC in Parallel
Total current is the
vector sum of the
currents in each
element.