Appliances and Efficiency

Question 1

What is the equation for energy transferred from the mains, E (joules, J)?

Answer 1

Power, P (watts, W) x Time, t (seconds, s)

Question 2

What is the equation for potential difference, V (volts, V)?

Answer 2

Power, p (watts, W) / Current, I (amperes, A)

Question 3

What is the standard equation for efficiency?

Answer 3

(Output power / Input power) x 100