A step-up transformer at a power station converts a voltage of 25,000 V25,000\text{ V}25,000 V to 400,000 V400,000\text{ V}400,000 V for power transmission across the National Grid.
Explain how the design of this transformer enables the voltage to be stepped up from 25,000 V25,000\text{ V}25,000 V to 400,000 V400,000\text{ V}400,000 V.
Your answer should include: