4.1 Simple Phenomena of Magnetism

Question 1

what is a magnetic field

Answer 1

space around a magnet

Question 2

direction of flow

Answer 2

north to south

Question 3

magnetic forces

Answer 3

forces caused by the interaction of magnetic fields

Question 4

whats a magnetic material

Answer 4

a material that experiences a force when placed in a magnetic field

Question 5

examples of magnetic materials

Answer 5

steel, cobalt, iron nickel

Question 6

what are magnetically soft materials

Answer 6

materials that can easily loose and gain magnetism- used for making electromagnets

Question 7

what are magnetically hard materials

Answer 7

materials that cannot easily loose and gain magnetism- used for making permanent magnets

Question 8

magnet induction

Answer 8

when a magnet is temporarily magnetized by being placed in a magnetic field

Question 9

ways of creating a magnet

Answer 9

1- stroking with a magnet
2- using direct current in a coil
3- hitting with a hammer in a magnetic field

Question 10

Methods of Demagnetisation

Answer 10

1- hitting with a hammer outside a magnetic field
2- Heat the material (until it begins to glow) and then slowly let it cool
3-Place the material in a coil containing alternating current (a.c.) and then slowly withdraw the material (with the a.c. power source still attached to the coil)

Question 11

advantages of electromagnets

Answer 11

1- they can be turned on and of

2- magnetic field strength can be changed

Question 12

how can the magnetic field of an electromagnet be increased

Answer 12

1- Increasing the current in the coil

2- Adding more turns to the coil

Question 13

what does an electromagnet consist of

Answer 13

a coil of wire surrounding a soft iron core

Question 14

non-ferrous metal

Answer 14

a metal that does not contain iron

Question 15

ferrous metal

Answer 15

a metal containing iron- therefore magnetic sksks