LMP1 6c 6d electromagnetism

Question 1

what does an electric current in a conductor produce?

Answer 1

a magnetic field

Question 2

what is the motor effect?

Answer 2

a current- carrying wire or coil can extent a force on a permanent magnet

Question 3

when does a motor effect occur?

Answer 3

when a wire with current flowing through it is placed in a magnetic field and experiences a force

Question 4

why is a force exerted on a current-carrying wire in a magnetic field?

Answer 4

the force increases if the strength of the magnetic field and or current increases

Question 5

what is the generator effect or electromagnetic induction?

Answer 5

when a voltage or potential difference is induced by moving a coil through a magnetic field

Question 6

when can you only see the generator effect?

Answer 6

when the wire passes trough the magnetic field, so up and down not along

Question 7

what does the size of the induced potential difference rely on?

Answer 7

larger if

• there is a stronger field
• if the wire moves more rapidly
• if we shape the wire into a coil (higher no. of coil the greater the induced voltage)

Question 8

when does the induced potential difference direction change?

Answer 8

when the magnets or the coils are going in different directions, up or down `

Question 9

what does the induced current create?

Answer 9

its own magnetic field
the field opposes the movement of the magnet
when putting north side into the coil that also becomes north, pulling it out makes it south

Question 10

how do you generate a current as well?

Answer 10

by closing the wires to make a circuit, the potential difference would generate a current
because of electron flow

Question 11

what does the transformer do?

Answer 11

changes the size of an alternating voltage by having different number of turns on the input and output sides

Question 12

what are the structures in transformers?

Answer 12

• a primary coil
• a secondary coil
• and an iron core

Question 13

how do transformers work?

Answer 13

at the primary coil
- alternating potential diff is applied on it
- causes flow of current 
- then a magnetic field 
iron core
- the field, induces an alternating magnetic field 
secondary coil
- it induces a potential difference 
- then it causes current to flow

Question 14

how and why are step up transformers and step down transformers used?

Answer 14

the step up transformers increases the voltage from the energy from the power station
once passing through wires and pylons it goes to the step down transformers to decrease the voltage for safe use