P4.1 Flashcards
What are magnetic field lines?
A way of modelling a field as they represent magnetic
What is magnetic flux density?
The number of files lines passing through an area - also called magnetic field strength
What does the density of field lines show?
The strength of the magnetic field
How do you draw arrows of 2 magnets?
They point out the north to the south
In terms of the domain model, what is a permanent magnet?
Many small magnetic regions (domains) that all line up
What happens in a (hard) magnetic material after you have induced it?
The small magnetic regions (domains) continue to be lined up
What happens in a (soft) magnetic material after you have induced it?
The domains return to their original position
What do the domains look like in an unmagnetised object?
They face random directions
What does a compass point to?
The magnetic North Pole
What is the “dip”?
The angle between field lines and a line horizontal to the surface of the earth (line in the middle of the N and S)
If the current is going into the page (dot) which way do the magnetic field lines go?
Anti-clockwise
How is the current going towards you shown on a page?
As a dot
What does the current going away from you look like on a page?
An “x” symbol
What does the “x” symbol suggest about the magnetic field lines?
The current is going away from you so the current goes clockwise
What does the strength of the field around a wire depend on?
The magnitude of the current - bigger current means bigger field
Distance from the wire - closer to wire means stronger field
