P1.3 The usefulness of electrical appliances

Question 1

How do you calculate the total cost of electricity?

Answer 1

total cost = number of units × cost per unit

For example, if 5 units of electricity are used at a cost of 8p per unit, the total cost will be 5 × 8 = 40p.

Question 2

How do you calculate the number of units?

Answer 2

units (kWh) = power (kW) × time (h)