Week 2 Maxwell's Equations

Question 1

what are the two sources in electromagnetism

Answer 1

charge density

current density

Question 2

define current

Answer 2

rate of loss of charge (flux) through a surface

Question 3

what two things are true of charge

Answer 3

charge is conserved

charge is Lorentz invariant

Question 4

what is the continuity equation

Answer 4

ρ^ + ∇ * j = 0

Question 5

what is the transport equation and define its components

Answer 5

I = -nev ∫dS
I is current
n is the number density
e is the elementary charge
v is the drift velocity

Question 6

define the Lorentz force law

Answer 6

f = E + v x B

f is the force per unit charge

Question 7

what is the electromagnetic energy density in vacuum

Answer 7

u = 1/2 ε0 |E|^2 + 1/2μ0 |B|^2

Question 8

what is the electromotive force equation

Answer 8

ε = ∫E*dl

Question 9

what is the Maxwell equation of Gauss’ Law

Answer 9

∇*E = ρ/ε0

Question 10

what is the Maxwell equation for no magnetic monopoles

Answer 10

∇*B = 0

Question 11

what is the Maxwell equation for Faraday’s Law

Answer 11

∇xE + B = 0

Question 12

what is the corrected Maxwell-Ampere equation

Answer 12

∇xB - μ0ε0E^ = μ0j

Question 13

why is the Maxwell-Ampere correction important

Answer 13

it gives us the exact speed of light from

1/μ0ε0 = c^2