Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/19

Click to flip

19 Cards in this Set

  • Front
  • Back

Magnets

Like poles repel


Opposite poles attract

Magnets....

Attract Iron





Lodestones:

Natural magnets



Domains:

Can break up with heat or violence



Soft iron:

Has domains, but usually they aren't ordered

Compasses:

Easy to pivot magnet that aligns with the Earth





How to make a compass:

Magnet, needle, cork



Force on moving charges....

are perpendicular to both magnetic field and direction of motion

If a charged particle moves from the bottom of the board to the the top, and the magnetic field is coming out of the board, the force is in the...

Left-right direction

Force on current carrying wires..

is the same as moving charges




Charges are moving IN the wires



Electromagnetic Induction:

Move a magnet through a coil, get a voltage



Faraday's Law:

Voltage increases with size of loops, number of loops, and how quickly the magnetic field changes.

REMEMBER!

It's not how strong a magnetic field is, but how fast it is changing!




(A strong field can help it change faster)

Energy Conservation:

Magnet doesn't want to go into loop

Generators

Motors running backwards




More resistance attached, harder to turn

Transformers

Primary and secondary coils




Side with more coils has higher voltage BUT lower current




MUST have changing current to work

Ignition system:

Really fast changing current


1. Breaker points cause fast change in primary


2. Lots of turns in secondary


3. Big voltage in secondary


4. Spark plug fires

When a bar magnet is thrust into a coil of copper wire, the coil tends to

Repel the magnet as it enters



A transformer actually transforms...

VOLTAGE