An electrified railway corridor requires 120 MW120\ \text{MW}120 MW of electrical power. Engineers are considering transmitting this power along a cable route at either 24 kV24\ \text{kV}24 kV or 240 kV240\ \text{kV}240 kV.
The total resistance of the cable route is 0.80 Ω.
For the proposed 240 kV240\ \text{kV}240 kV arrangement, calculate the current carried by the cable route.
For this arrangement, calculate the rate at which energy is dissipated in the cable route.
The alternative arrangement uses 24 kV24\ \text{kV}24 kV. Show that the rate of energy dissipation in the cable route would be 100 times the value for the 240 kV240\ \text{kV}240 kV arrangement.
For the 240 kV240\ \text{kV}240 kV arrangement, calculate the percentage of the power required by the railway corridor that is dissipated in the cable route.
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.