Notes and Review. Some is old and some is new Pay attention and pass the test Sit in your assigned seats. Shape of Magnetic Fields. There are two poles, North and South. They are connected by magnetic field lines. Attraction and Repulsion.
Some is old and some is new
Pay attention and pass the test
Sit in your assigned seats
The poles of two magnets that are different or opposite will attract. Magnetic lines of force from north and south poles pull together and join. ...out of north end and into south end...
The poles of two magnets that are the same will repel or push each other apart. ...out of both north ends - repelling or pushing each other apart...
Electromagnets are made of coils of wire with electricity passing through them. Moving charges create magnetic fields, so when the coils of wire in an electromagnet have an electric current passing through them, the coils behave like a magnet. When the electricity stops flowing, the coils don’t act like a magnet anymore.
What makes an electromagnet stronger?
Think about what makes an electromagnet?
When the voltage switches between positive (+) and negative (-), this is called ______________________, or ____. If the voltage is constant, as with a battery, this is called _______________________, or ____.
To cause the rotor to turn in a counter-clockwise direction, the north pole of an electromagnet should be placed at position:
The Electromagnet’s North must push (repel) a North on the rotor and/or pull (attract) a south on the rotor
This happens at “A”
A transformer is composed of 3 things
When the turns in the secondary coil go up, the voltage _________________. This is called a ___________ transformer. When the voltage in the secondary coil goes up, the current must go _______________, because ________________________________________________________.
Transformers can not increase energy, because of the Law of Conservation of Energy.
If the ratios are always the same, then we can set them equal to each other, like this:
In other words the ratio of turns is equal to the ratio of voltages.