the national grid.

Question 1

what is TNG?
(TNG is my abbreviation of the national grid and not an official one so don’t use it for exams.)

Answer 1

system of cables and transformers linking power stations to homes and businesses.

Question 2

what are the stages of TNG?
( don’t worry about them being in order for this question.)

Answer 2

power station.
step up transformer.
transmission cables.
step down transformer.
house, shops, etc.

Question 3

what is the correct order of the components in TNG?

Answer 3

power station.
step up transformer.
transmission cables.
step down transformer.
house, shops, etc.

Question 4

how many volts go through a power station.

Answer 4

25,000 v.
400,000 v.
230 v.

Question 5

what is the function of a power station?

Answer 5

transfers energy supply into electrical energy.

Question 6

what is another name for power station?

Answer 6

power plant.

Question 7

what is the function of a step up transformer?

Answer 7

increase potential difference from power station to transmission cables.
reduces current, reduces the heating effect caused by current flowing in the trans cables.
reduce heat effect, reduce energy loss, transmission more efficient.

Question 8

what is the function of the transmission cables?

Answer 8

transfer electricity.

Question 9

what is the function of step down transformers?

Answer 9

reduce the potential difference from the transmission cables to a much lower value for domestic use.

Question 10

is the power transmitted through the national grid at high or low voltage and why?

Answer 10

high.
reduce energy loss through heating.

Question 11

what happens when a current flows in a wire in terms of electrons and what does this result in?

Answer 11

electrons bump into atoms that make up the wire.
some of their energy is transferred to the atoms in the wire during this process.
results in: temperature of wire increasing.

Question 12

what does the law of conservation of energy mean?

Answer 12

electrons have less energy to power the lights, kettles etc in our homes.

Question 13

what is the equation for power transmitting to an appliance?

Answer 13

power= current × potential difference.

Question 14

if we were to transfer power along the national grid what can we reduce, how and what’s the outcome?

Answer 14

current flowing by increasing the voltage and still transfer the same power.

Question 15

How is the national grid more efficient?

Answer 15

using small amounts of large stations are more efficient than using a large amount of small stations.
use steam turbines which are more efficient at higher temps.