This question is about using the mains electricity supply - Edexcel - GCSE Physics - Question 5 - 2021 - Paper 1

To calculate the energy transferred to the coffee machine, we use the formula:

$E = I \times V \times t$

Where:

• $I = 7.4 \, \text{A}$
• $V = 230 \, \text{V}$
• $t = 120 \, \text{s}$

Substituting these values into the equation:

$E = 7.4 \times 230 \times 120$

Evaluating gives:

$E \approx 203,040 \, \text{J}$

Therefore, the energy transferred to the coffee machine is approximately 200,000 J.

Wire X = neutral
Wire Y = live

Component Z = fuse

To find the input current, we use the equation:

$\text{input current} \times \text{input voltage} = \text{output current} \times \text{output voltage}$

Rearranging gives:

$\text{input current} = \frac{\text{output current} \times \text{output voltage}}{\text{input voltage}}$

Substituting in the values:

$\text{input current} = \frac{2.37 \, \text{A} \times 190 \, \text{V}}{230 \, \text{V}}$

Calculating this yields:

$\text{input current} \approx 1.95 \, \text{A}$

Hence, the input current to the transformer is approximately 1.95 A.