electromagnetism

Question 1

what happens when current flows through a conducting wire?

Answer 1

magnetic field is produced around the wire

Question 2

how can we prove their in a magnetic field around wire by using a compass?

Answer 2

when current is turned off, compass lines up with earth’s magnetic field
if we turn current on, compass traces direction of magnetic field

Question 3

how can we increase strength of magnetic field?

Answer 3

coiling wire into a shape called solenoid
increase size of current
moving closer to wire

Question 4

what happens if we change direction of current?

Answer 4

we change direction of magnetic field

Question 5

how can we work out direction of magnetic field produced by wire?

Answer 5

right hand grip rule
place right hand so thumb is in direction of current, now fingers are curling in direction of magnetic field

Question 6

what are the 3 ways we can increase strength of magnetic field produced by a solenoid?

Answer 6

increase size of current
increase number of turns in coil
place piece of iron inside solenoid ( iron core)

Question 7

what is an electromagnet?

Answer 7

solenoid containing an iron core

Question 8

why are electromagnets useful?

Answer 8

can change strength of magnetic field by changing size of current
can also turn electromagnet on or off