Identify the parts of the transformer labelled in Figure 12 - AQA - GCSE Physics - Question 7 - 2022 - Paper 1

Using the transformer equation, we have $\frac{V_s}{V_p} = \frac{N_s}{N_p}$ Here, let:

• $V_p = 230 \, V$
• $N_p = 1200$ (turns in primary coil)
• $N_s = 200$ (turns in secondary coil)

Based on the equation, we can find $V_s$: $V_s = V_p \times \frac{N_s}{N_p} = 230 \, V \times \frac{200}{1200}$ $V_s = 138.0 \, V$

The alternating current causes a changing magnetic field around the primary coil. This changing magnetic field induces an alternating potential difference across the secondary coil, which in turn results in an alternating current flowing in the circuit.

The direction of the force is: down.

Using the formula: $F = BIL$ Where:

• $F = 0.045 \, N$
• $B = 60 \times 10^{-6} \, T$
• $I = 50 \, A$

Rearranging for $L$ gives: $L = \frac{F}{BI} = \frac{0.045}{60 \times 10^{-6} \times 50} \approx 15 \, m$

The wire is straight and the force is constant.