The transformer in another battery charger has a primary coil and a secondary coil - Edexcel - GCSE Physics Combined Science - Question 4 - 2020 - Paper 1

To calculate the primary current, we will use the formula provided:

ext{primary current} = rac{ ext{secondary voltage} imes ext{secondary current}}{ ext{primary voltage}} = rac{15 ext{ V} imes 3.1 ext{ A}}{230 ext{ V}}

Now, we perform the calculation:

1. Calculate the numerator: $15 ext{ V} imes 3.1 ext{ A} = 46.5 ext{ VA}$
2. Divide by the primary voltage: = 0.202 ext{ A}$$

Thus, the current in the primary coil is approximately 0.202 A.