Question

A heater coil is rated 100 w , 200 v. if it is cut in two identical parts and both parts are connected in parallel with the same source of 200 V . Calculate the energy liberated per sec in the new combination

Answer 1

power rating,m P = 100 Wvoltage supply, V = 200Vthus resistance of the coil:P = V2 / Rthus R = 40000/100 = 400 ohmhence of the two new parts produced, new resistance of each part, R' = 200 ohm eachon parallel connection, net resistance:1/Rt = 1/R' + 1/R'hence Rt = R'/2 = 100 ohmand the new power rating, P = V2 /Rt = 40000/100 = 400 W