Figure 4 shows the inside of a mains plug - Edexcel - GCSE Physics - Question 2 - 2020 - Paper 1

The meter on the battery charger is A an ammeter as it measures the current supplied to the battery.

To calculate the charge flowing to the battery, we use the equation:

$\text{charge} = \text{current} \times \text{time}$

1. Convert 8 minutes to seconds: $8 \text{ minutes} = 8 \times 60 = 480 \text{ seconds}$

2. Substitute the values into the equation: $\text{charge} = 2.5 \text{ A} \times 480 \text{ s} = 1200 \text{ C}$

Thus, the charge flowing to the battery in 8 minutes is 1200 C.

To find the current in the primary coil, we again use the equation:

$\text{primary current} = \frac{\text{secondary voltage} \times \text{secondary current}}{\text{primary voltage}}$

Substituting the known values:

• Secondary voltage = 15 V
• Secondary current = 3.1 A
• Primary voltage = 230 V

$\text{primary current} = \frac{15 \text{ V} \times 3.1 \text{ A}}{230 \text{ V}} \approx 0.20217 \text{ A}$

Rounding to 2 decimal places, the primary current is approximately 0.20 A.