magnetism+ elecrtomagnetism

Question 1

two types of poles

Answer 1

north

south

Question 2

like poles..

Answer 2

repel

Question 3

unlike poles..

Answer 3

attract

Question 4

magnetic field =

Answer 4

region around the magnet

Question 5

strength of field depends on…

Answer 5

distance from magnet

Question 6

permanent magnets

Answer 6

produce their own magnetic field

Question 7

induced magnets

Answer 7

become a magnet when placed in a magnetic field

Question 8

density of the field lines =

Answer 8

flux density

Question 9

flux density indicates

Answer 9

the strength of the field at that point

Question 10

higher flux density =

Answer 10

stronger the field and greater the force

Question 11

compass needle aligns…

Answer 11

with the earths magnetic field
(points north)
-> provides evidence that earth core is magnetic

Question 12

plotting fields

Answer 12

1) place bar magnet on paper
2) place compass at 1 end
3) mark where point of compass needle is
4) move compass so the rail is at the point that has been marked
5) mark new point where needle is
6) repeat and connect the marks until full field is plotted

Question 13

when current flows in a conducting wire:

Answer 13

a magnetic field is produced around the wire

Question 14

direction of field lines depends on

Answer 14

the direction of the current

Question 15

right hand grip method:

to find direction of field lines

Answer 15

-grip wire in right hand
(thumb pointing in direction of the current)
-fingers curled around the wire will point in the direction field lines should be drawn

Question 16

strength of field depends on..

Answer 16

size of current and distance from wire

Question 17

a solenoid is formed:

Answer 17

when wire is looked into a cylindrical coil

Question 18

solenoid:

Answer 18

increases the strength of magnetic field

Question 19

to further increase field strength:

Answer 19

add iron core

Question 20

when you add an iron core to increase field strength is creates an..

Answer 20

electromagnet

Question 21

the solenoid increases magnetic field strength because:

Answer 21

• it concentrates a longer piece of wire into a smaller area

- the looped shape means that the magnetic field lines around the wire are in the same direction

Question 22

right hand grip method:

to find north pole of solenoid

Answer 22

• hold solenoid in right hand with your fingers following direction of current flows
• your thumb will point the north pole of solenoid