An electric heater has a resistance of 40Ω and draws a current of 4A

1.	An electric heater has a resistance of 40Ω and draws a current of 4A. Calculate : 1. its power 2. p.d. at its ends
Answer» (i) Power P = I²R, R = 40Ω I = 4A P = 4 x 4 x 40 = 640W (ii) P.d. at its ends V = p/I = 640/4 = 160V

An electric heater has a resistance of 40Ω and draws a current of 4A. Calculate : 1. its power 2. p.d. at its ends

Answer»

(i) Power P = I²R, R = 40Ω

I = 4A

P = 4 x 4 x 40 = 640W

(ii) P.d. at its ends V = p/I = 640/4 = 160V