What is the current through an 8Ω toaster when it is operating on 240V?
Answer:
(In this question, 2 physical quantities are given, they are the "240V" and "80Ω". The question doesn't tell what quantites they are. However we can recognise these quantities from its unit. Ω is the unit of resistance whereas V is the unit of potential difference.)
Resistance, R = 80Ω
Potential difference, V = 240V
Current, I = ?
V = IR
(240) = I(80)
I = 3A