transformers - PAPER 2

Question 1

how are transformers used in the national grid?

Answer 1

• once the power stations have generated the electricity, it has to be passed through step up transformers, which increase the voltage to around 400,000 V

Question 2

what does a step up transformer mean

Answer 2

it is an electrical device that increases alternating current voltage from a lower to a higher level, while also reducing the current

Question 3

what is the point of using a step-up transformer while generating electricity?

Answer 3

it is important for maximising the efficiency as it minimizes the energy loss during long-distance transmission

Question 4

what happens once the electricity passes where it needs to such as a town?

Answer 4

it passes through a step-down transformer, which decreases the voltage to around 230 V so that its safe to use in homes

Question 5

what is the role of a transformer?

Answer 5

it is to increase or decrease the voltage of electricity

Question 6

how does a transformer work?

Answer 6

by using electromagnetic induction to transfer electricity between coils through a magnetic field, such as an iron core

Question 7

what does the alternating current in the primary coil create, which will lead to what?

Answer 7

the alternating current in the primary coil will create a changing magnetic field, leading to a voltage in the secondary coil

Question 8

in simple terms, what is the transformer basically doing to the primary and secondary coil?

Answer 8

it is essentially transferring the current from the primary coil to the secondary coil

Question 9

what will happen to the voltage in the secondary coil of a STEP UP transformer and why?

Answer 9

it doubles as there are double the amount of coils in the secondary coil

Question 10

what will happen to the voltage in the secondary coil of a STEP DOWN transformer and why?

Answer 10

it halves as there are half the amount of coils in the secondary coil

Question 11

for transformers to work, the current in the primary coil must be what type of current?

Answer 11

it must be an alternating current

Question 12

in a transformer calculation, what does the following letters mean:
-‘V’
-‘n’
-‘I’
-‘p’
-‘s’

Answer 12

• ‘V’ - potential difference
• ‘n’ - number of turns of the coil
• ‘I’ - current
• ‘p’ - primary
  -‘s’ - secondary