Presentation is loading. Please wait.

Presentation is loading. Please wait.

Magnetic Induction Transforming energy with magnetism.

Similar presentations


Presentation on theme: "Magnetic Induction Transforming energy with magnetism."— Presentation transcript:

1 Magnetic Induction Transforming energy with magnetism

2 Lorentz Force Reminder F = qv  B Source: Griffith, The Physics of Everyday Phenomena F is directed out of the screen.

3 CPS Question B I What is the direction of the Lorentz force on the charges moving in this wire? A. B. C. D. E. F.

4 – Moving Creates a Potential v B induced potential +

5 Motional emf Moving a conductor through a magnetic field causes separation of charges. Back-emf (motional emf) in conductor cancels potential from motion  = l vB when l, v, B all orthogonal

6 Rotating Loop Creates Circuit B V V

7 B V V

8 Group Work a.At which position(s) does the most magnetic flux pass through the loop? b.At which position(s) does the magnetic flux through the loop change the fastest? abcde

9 Group Work c.What is the current direction at these points? abcde

10 Faraday’s Law Greatest flux  when perpendicular Fastest change in flux  /  t when parallel abcde

11 Rotation Powers a Generator v v Motion V V induces a potential which generates a current that charges the battery B through the field

12 Lenz’s Law Explains Generator   B changing field opposing field needed I

13 Current in a Field Feels a Force F B I

14 Loop in a Field Has Torque B I I

15 Torque Turns a Motor I I current I force F B

16 Group Work If the magnetic field intensifies, in what direction will the induced current be? B Which direction is the flux change? What current would oppose it? What is the Lorentz force on each side?

17 How a Microphone Works microphone geophone Flux inside loop becomes more

18 How a Loudspeaker Works loudspeaker induced motion of magnet current current- generated field attracts or repels magnet

19 Back Potential As the motor turns, back-potential  B /  t opposes  Faster rotation  more back potential  I B


Download ppt "Magnetic Induction Transforming energy with magnetism."

Similar presentations


Ads by Google