Magnetism Flashcards
(43 cards)
What is magnetism?
Magnetism is a non-contact force that can attract or repel certain materials without touching them.
Which materials are magnetic?
Materials like iron, nickel, cobalt, and steel are magnetic
What are magnetic poles?
Every magnet has two poles: a north pole and a south pole.
What happens when like poles or unlike poles interact?
Like poles repel, and unlike poles attract.
What is a magnetic field?
It is the area around a magnet where magnetic forces are felt.
How can we see magnetic fields?
Using iron filings or a compass, which show the shape of the magnetic field.
Which direction do magnetic field lines go?
From the north pole to the south pole of a magnet.
What are induced magnets?
Materials that become temporary magnets when placed in a magnetic field.
What happens to induced magnetism when the magnetic field is removed?
The induced magnetism disappears.
How do compasses work?
A compass uses a small magnet to align with the earth’s magnetic feild, pointing towards the magnetic North.
What creates the magnetic field in an electromagnet?
The electric current flowing through the wire coil (solenoid) creates the magnetic field.
What is a solenoid?
A solenoid is a coil of wire that produces a magnetic field when current flows through it.
What role does the nail play in an electromagnet?
The nail becomes magnetized and strengthens the magnetic field produced by the solenoid.
What happens when you turn off the current in an electromagnet?
The magnetic field disappears, and the nail stops acting like a magnet.
Why is the magnetic field called an electromagnetic field?
Because it is created by the electric current flowing through the wire, not by a permanent magnet.
What happens if you reverse the current in a solenoid?
The north and south poles of the electromagnet swap places.
What are the 3 main factors that affect the strength of an electromagnet?
The number of coils (turns of wire)
The size of the electric current
The presence of an iron core (like a nail)
What happens if you increase the number of coils in a solenoid?
The magnetic field becomes stronger.
What happens if you increase the electric current in the wire?
The magnetic field becomes stronger, so the electromagnet is more powerful.
Why is an iron core (like a nail) placed inside a solenoid?
It concentrates and strengthens the magnetic field, making the electromagnet much stronger.
True or false the earth has a magnetic feild
True
Why do we often make salts using reaction rather than extracting them from nature?
Salts found in nature are limited and will run out
Recite the methods of extracting salts
Evaporation: Collect it in small ponds- water will soon evaporate leaving salts behind
Salt mining: Salts left from dried up seas get dug underground overtime. This is collected by miners.
Solution mining: Underground rivers collect brim (salty water) this is pumped up and salt is seperated from the water.
name a useful property for Aluminium
Heat conductor
