Figure 8 shows how electricity is supplied to consumers by the National Grid - AQA - GCSE Physics - Question 6 - 2022 - Paper 1

Transformer Y is used in the National Grid to decrease the potential difference to a safer and more manageable level for consumers. This step is crucial for ensuring that the voltage is appropriate for household and commercial use, thereby protecting electrical appliances and ensuring safety.

To find the charge flow (Q), we can use the formula relating energy (E), charge (Q), and potential difference (V):

$E = Q \times V$

Rearranging gives:

$Q = \frac{E}{V}$

Substituting the given values:

1. $E = 3.24 \times 10^{11} \text{ J}$
2. $V = 230 \text{ V}$

Calculating:

$Q = \frac{3.24 \times 10^{11}}{230} \approx 1.408695652 \times 10^{9} \text{ C}$

Rounding to three significant figures:

$Q \approx 1.41 \times 10^{9} \text{ C}$