Electromagnetic Induction - PowerPoint PPT Presentation

Loading...

PPT – Electromagnetic Induction PowerPoint presentation | free to download - id: 3adf9d-OTg0N



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Electromagnetic Induction

Description:

Electromagnetic Induction Physics La Ca ada High School Dr.E Electromagnetic Induction Motors/Generators http://science.howstuffworks.com/motor4.htm Faraday s Law ... – PowerPoint PPT presentation

Number of Views:22038
Avg rating:3.0/5.0
Slides: 33
Provided by: MarkEwol
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Electromagnetic Induction


1
Electromagnetic Induction
  • Physics
  • La Cañada High School
  • Dr.E

2
  • Electromagnetic Induction
  • Motors/Generators http//science.howstuffworks.com
    /motor4.htm
  • Faradays Law
  • Transformers
  • Power Transmission
  • Solenoids
  • MRI

3
The Magnetic Field
  • The electric field proves a useful concept to
    explain the effects of charge at a distance
    (explains how one charge knows another charge is
    there).
  • Stationary charges produce only an electric field
  • Moving charges (in flux) produce both an electric
    field and a magnetic field

4
  • Electromagnetic Induction
  • Motors/Generators http//science.howstuffworks.com
    /motor4.htm
  • Faradays Law
  • Transformers
  • Power Transmission
  • Solenoids
  • MRI

5
Motors
  • Motors work due to two major principles
  • Opposite poles attract while like poles repel
  • Current running through a coiled wire creates a
    magnet

6
Theory
7
Mechanics
8
(No Transcript)
9
  • Electromagnetic Induction
  • Motors/Generators http//science.howstuffworks.com
    /motor4.htm
  • Faradays Law
  • Transformers
  • Power Transmission
  • Solenoids
  • MRI

10
Faradays Law of Induction
  • The voltage induced in a coil is proportional to
    the number of coils times the magnetic flux (rate
    at which the magnetic field changes)

11
Wrap Rule to find Magnetic Field
  • Wrap your fingers in the direction of the current
  • The magnetic field points in the direction of the
    thumb (to the left)
  • Since the field lines leave the left end of
    solenoid, the left end is the North pole

12
(No Transcript)
13
  • An ammeter is connected in a circuit of a
    conducting loop
  • When a bar magnet is moved closer to, or farther
    from, the loop, an electromotive force (emf) is
    induced the loop
  • The ammeter indicates currents in different
    directions depending on the relative motion of
    magnet and loop
  • When the magnet stops moving, the current returns
    to zero as indicated by the ammeter

14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
  • Electromagnetic Induction
  • Motors/Generators http//science.howstuffworks.com
    /motor4.htm
  • Faradays Law
  • Transformers
  • Power Transmission
  • Solenoids
  • MRI

19
Primary Voltage of 1o turns
Secondary Voltage of 2o turns
20
(Power IN)
(Power OUT)
21
(Voltage x Current)secondary
(Voltage x Current)primary
22
  • Electromagnetic Induction
  • Motors/Generators http//science.howstuffworks.com
    /motor4.htm
  • Faradays Law
  • Transformers
  • Power Transmission
  • Solenoids
  • MRI

23
Power Transmission
  • Plant
  • 6000 V and 20Amps
  • Local and Homes
  • 120 V and 100 Amps
  • Low Voltage Wires
  • 2200 V and 54 Amps
  • High Voltage Wires in Town
  • 120,000 V and 1 Amp
  • Ultra High Voltage
  • 400,000 V and 0.3 Amps

24
  • Electromagnetic Induction
  • Motors/Generators http//science.howstuffworks.com
    /motor4.htm
  • Faradays Law
  • Transformers
  • Power Transmission
  • Solenoids
  • MRI

25
Solenoids
  • The magnetic field of a solenoid is essentially
    identical to that of a bar magnet.

The big difference is that we can turn the
solenoid on and off ! It attracts/repels other
permanent magnets it attracts ferromagnets, etc.
26
(No Transcript)
27
Solenoid Applications
  • Digital on/off
  • Doorbells
  • Power door locks
  • Magnetic cranes
  • Electronic Switch relay
  • Advantage
  • A small current can be used to switch a much
    larger one
  • Starter in washer/dryer, car ignition,

28
Solenoid Applications
  • Analog (deflection a I )
  • Variable A/C valves
  • Speakers

Solenoids are everywhere!
29
  • Electromagnetic Induction
  • Motors/Generators http//science.howstuffworks.com
    /motor4.htm
  • Faradays Law
  • Transformers
  • Power Transmission
  • Solenoids
  • MRI

30
Thanks to
31
MRI / NMR
If we bathe the protons in radio waves at a
particular frequency, the protons can flip back
and forth. If we detect this flipping ?
hydrogen! The presence of other molecules can
partially shield the applied magnetic field, thus
changing the resonant frequency (chemical
shift). Looking at what the resonant frequency
is ? what molecules are nearby. If a strong
magnetic field gradient is produced across the
sample, can look at individual slices, with
millimeter spatial resolution.
32
Bibliography
  • Magnetism Examples of Magnetic Field
    Calculations, Innovations in Undergraduate
    Physics Education at Illinois _at_
    online.physics.uiuc.edu/courses/phys112/spring04/
    Lectures/Lect15.ppt, 4/17/04
About PowerShow.com