A solar farm transmits an electrical power of 24 MW24\ \mathrm{MW}24 MW for 1.5 h. Two transmission systems are considered.
| System | Potential difference | Total cable resistance |
|---|---|---|
| A | 120 kV120\ \mathrm{kV}120 kV | 8.0 Ω |
| B | 240 kV240\ \mathrm{kV}240 kV | 12 Ω |
Calculate the energy dissipated in the cables of each system during the 1.5 h, and the percentage by which system B reduces the energy dissipated compared with system A.
108 exam-style questions on Edexcel GCSE Physics 13.2 Transformers and the National Grid, covering 13.2.1 Transformers and induction, 13.2.2 The transformer turns-ratio equation, 13.2.3 The National Grid, 13.2.4 The transformer power equation, and 13.2.5 Advantages of high-voltage transmission. Each one has a worked solution and a mark scheme showing where the marks go.