Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Maxwell Equation
Chapter 8
1
Chapter 7 Magnetostatic Field
7
...
2 Displacement Current
Michael Faraday
2
3
Michael Faraday in his laboratory, ca
...
4
Faraday Cage
Animation showing how a Faraday cage (box)works
...
These induced charges create an opposing electric
5
field that cancels the external electric field throughout the box
...
7
In Summary
The electrostatics fields are usually
produced by static electric charges
Magnetostatic fields are due to motion of
electric charges with uniform velocity
(steady current) or static magnetic charges
(magnetic poles)
Electromagnetics fields or waves are
usually due to accelerated charges or time
varying currents
8
timeVarious type of time-varying current
9
Faraday’s Law
Vemf
dλ
dψ
=−
= −N
dt
dt
N is the number of turns in the circuit
ψ is the flux through each turn
The negative sign shows that the induced voltage acts
in such a way as to oppose the flux producing it
...
11
Faraday’s Law Experiment 1831
On the right is a liquid battery that provides a current that flows
through the small coil of wire (A)creating a magnetic field
...
However, when
the small coil is moved in or out of the large coil (B), the change
in magnetic flux induces a current in the large coil
...
12
Faraday’s Law Experiment
13
Faraday’s Law Experiment
1
...
2
...
3
...
4
...
5
...
14
Faraday’s Law Experiment
6
...
7
...
]
8
...
Such a current is called an induced current
15
Faraday’s Law
•
•
•
•
There are other kinds of electric fields not directly
caused by electric charges
...
16
Transformer and Motional
EMFs
Transformer and Motional EMFs
How Faraday’s law links electric and magnetic
fields
...
dl = − ∫ Bid S
dt S
L
has been replaced by
∫
S
Bid S
18
Variation of flux with time
•
Stationary loop in a time varying B field
(Transformer emf)
•
Moving Loop in Static B field ( Motional emf)
•
Moving Loop in Time-Varying Field
19
Stationary loop in a time varying B field
•
This emf induced by time-varying current
(producing the time varying B field) in a stationary
loop is often referred as transformer emf
Vemf
∂B
= ∫ E
...
dl =
∫ ( u × B )
...
Both transformer emf and motional emf are
present
Vemf
∂B
= ∫ E m
...
dl
L
∂B
∇× E = −
+ ∇ × (u × B)
∂t
22
Example 1
A conducting circular loop of radius 40 cm lies in the y = 0
plane in a magnetic field
Calculate the induced voltage in the loop
...
Calculate the induced emf V2 in the secondary
coil
25
Example 4
26