5 (a) Complete the sentence by putting a cross (X) in the box next to your answer - Edexcel - GCSE Physics - Question 5 - 2018 - Paper 1

Power can be calculated using the formula:

$$ext{Power (P)} = ext{Voltage (V)} imes ext{Current (I)}$$

To find the power of the electric heater:

$$P = 230 ext{ V} imes 9.2 ext{ A} = 2116 ext{ W}$$

Therefore, the power of the electric heater is 2116 W.

First, find the energy consumed by the computer in kWh:

ext{Energy (kWh)} = rac{ ext{Power (W)}}{1000} imes ext{Time (h)}

Substituting in the values:

ext{Energy} = rac{350 ext{ W}}{1000} imes 4 ext{ h} = 1.4 ext{ kWh}

Next, calculate the cost:

$$ext{Cost} = ext{Energy (kWh)} imes ext{Cost per kWh}$$ $$ext{Cost} = 1.4 ext{ kWh} imes 20 ext{ p} = 28 ext{ p}$$

Thus, the cost of using the computer for 4 hours is 28 p.