Question

An electric heater has a resistance of R = 50ohms. It is connected across a power
supply of V = 240 V. for a period of T, I = 2 hr. Determine the work done (W) by
the power supply on the heater, How many ‘units' of electricity are consumed?

Answer 1

• $Energy=power\times time$

$=\frac{V^2}{R}\times 2 hours$

$=\frac{240^2}{50}\times 2=2304Wh$

Work done/ Energy= 2304Wh

• Units of electricity consumed

$=\frac{2304}{1000}=2.304KWH$

=2.304 units