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

Using the transformer equation: $\frac{V_s}{V_p} = \frac{N_s}{N_p}$

Given:

• Input pd ($V_p$) = 230 V
• The turns ratio is $\frac{N_s}{N_p} = \frac{1200}{200}$.

So, solving for $V_s$: $V_s = \frac{N_s}{N_p} \times V_p = \frac{1200}{200} \times 230 = 1380 \, V$

The alternating input causes a changing magnetic field around the primary coil, which creates a magnetic field that changes direction in the core. This induces an alternating potential difference across the secondary, causing an alternating current in the output.

Down

Using the formula for the force on a current-carrying conductor in a magnetic field: $F = B \cdot I \cdot L$ Given:

• Force ($F$) = 0.045 N
• Magnetic flux density ($B$) = 60 \times 10^{-6} , T
• Current ($I$) = 50 , A

Rearranging for length ($L$): $L = \frac{F}{B \cdot I} = \frac{0.045}{60 \times 10^{-6} \cdot 50} = 15 \, m$

The wire/force is at right angles to the magnetic field.