Transformers step up voltage for efficient power transmission

Steps:

• Power stations generate electricity at lower voltages; transformers adjust this for long-distance transmission.
• For efficient transmission, high voltage reduces current while keeping power constant (P = V × I).
• Step-up transformers increase potential difference (PD) from the power station.
• This decreases current, minimizing energy loss as heat (I²R losses) in cables.

Why C is correct:

• Transformers increase PD to high levels (e.g., 400 kV) and decrease current proportionally, per the transformer equation (V_p / V_s = N_p / N_s) and power conservation.

Why the others are wrong:

• A: Decreasing both increases losses, defeating transmission efficiency.
• B: Increasing both current and PD would waste energy without reducing losses.
• D: Increasing current while decreasing PD maximizes I²R losses, unsuitable for transmission.

Final answer: C