t7-magnetism

Question 1

explain magnetic fields
3 points

Answer 1

-it’s the region around a magnet where a force acts on another magnet
-the closer the field lines, the stronger the field (strongest at the poles)
-field lines go from N->S

Question 2

what is a permanent magnet
2 points

Answer 2

-produces their own magnetic field (can’t be turned on/off)
-can attract a magnetic material but can’t repel it

Question 3

what are the 3 magnetic elements

Answer 3

iron
nickel
cobalt

Question 4

what is an induced magnet
2 points

Answer 4

-becomes magnetic when placed in a field
-only attracted to other magnets, not repelled

Question 5

what are solenoids+describe it
4 points

Answer 5

• a coil of wire
  -magnetic field is strong and uniform
  -if it goes south, current is clockwise
  -if it goes north, current is anticlockwise

Question 6

rule for electromagnet magnetic fields
3 points

Answer 6

-right hand rule
-thumb up=current up=anticlockwise magnetic field
-thumb down=current down=clockwise magnetic field

Question 7

3 ways to increase strength of electromagnets

Answer 7

-increase current
-increase number of coils
-use a soft iron core-iron becomes induced by electricity