Complete the sentence by putting a cross (X) in the box next to your answer - Edexcel - GCSE Physics - Question 3 - 2017 - Paper 1

Electrical energy is transmitted at high voltages, because it improves the efficiency by reducing heat loss in the transmission lines.

To calculate the input power of the transformer, use the formula:

$P = V imes I$

Where:

• $P$ is the power,
• $V$ is the voltage (12 V),
• $I$ is the current (0.5 A).

Substituting in the values:

$P = 12 imes 0.5$

Evaluating gives:

$P = 6$

The unit of power is watts (W).