electromagnetism

Question 1

what are the two types of magnetism?

Answer 1

• induced magnetism
• permanent magnetism

Question 2

what is permanent magnetism?

Answer 2

they create their own magnetic field all the time

Question 3

what is induced magnetism?

Answer 3

when they only have a magnetic field temporarily

Question 4

what are the magnetic materials?

Answer 4

nickel, iron, cobalt, steel

Question 5

what is meant by soft magnets?

Answer 5

they lose their magnetism once they are outside the magnetic field

Question 6

what is meant by hard magnets?

Answer 6

they lose their magnetism very slowly

Question 7

what does the direction of the magnetic field depend on?

Answer 7

direction of the current

Question 8

solenoid

Answer 8

• it is a coil with many turns
• the magnetic field within a solenoid is strong and uniform
• it is an electromagnet

Question 9

why are electromagnetics useful?

Answer 9

there is only a magnetic field when there is a current flowing

Question 10

how to increase strength of magnetic field?

Answer 10

• increase the current
• increase the number of coils
• decrease the length (keep number of turns the same
• add an iron core inside the solenoid

Question 11

what is motor effect

Answer 11

the idea that a current carrying wire in the prescience of a magnetic field will rxperience a force

Question 12

motor effect

Answer 12

• when a magnetic field interacts with another magnetic field
• the wire has to be perpendicular to the magnetic field to have the full force

Question 13

flemmings left hand rule

Answer 13

• thumb upwards (direction of force)
• index finger forwards (direction of magnetic field)
• middle finger perpendicular to index (direction of current)

Question 14

equation for force

Answer 14

F = B x I x L

Question 15

what is magnetic flux density measured in?

Answer 15

Tesla (T)