Question

A 2.5 kW immersion heater is used to heat water. Calculate
(i)The operating voltage of the heater if its resistance is 24Ω
(ii) The electrical energy converted to heat energy in 2 hours.​

Answer 1

P=VI=I2R

I = (2500/24)1/2 =10.2062A

V=IR= 10.2062 * 24 = 244.9488V

E = VIt = Pt = 2500*2*60*60 = 1.8 * 107J

OR E= VIt = 244.9488 * 10.2062 * 2 * 60 * 60 = 1.8 * 107J