transformers

Question 1

where does the magnetic field produced in the primary coil go?

Answer 1

stays in the iron core and then nearly all passes through to secondary coil (hardly any lost)

Question 2

what does the alternating current in the primary coil lead to?

Answer 2

the magnetic field in iron core to change direction

Question 3

what does rapidly changing the magnetic field do?

Answer 3

it leads to the field being felt by the secondary coil

Question 4

what does changing the field do?

Answer 4

it induces an alternating potential difference across the secondary coil

Question 5

what does relative number of turns on 2 coils determine?

Answer 5

whether the potential difference in the secondary coil is more than the potential difference in the primary coil

Question 6

step down transformers

Answer 6

potential difference across secondary coil is less than potential difference across primary coil

Question 7

step up transformers

Answer 7

the potential difference across secondary coil is greater than potential difference across primary coil

Question 8

what would happen if u supplied direct current to primary coil?

Answer 8

the primary coil would make nothing because it needs a constantly changing magnetic field

Question 9

what is the iron core for?

Answer 9

• transferring the changing magnetic field from the primary to secondary coil
• no electrons flow around iron core

Question 10

what frequency do switch mode transformers operate at?

Answer 10

a high frequency - 50khz and 200khz

Question 11

why are switch transformers made to work at a higher frequency?

Answer 11

so they can be made much lighter and smaller

Question 12

uses of switch transformers?

Answer 12

-mobile phone chargers and power supplies

Question 13

how are switch transformers efficient?

Answer 13

they use very little power and ‘no load’ (don’t use energy unless thing charging or powering is applied)