Question

Two light bulbs are marked 230v,75w and 230v,150w. If the first bulb has a resistence R,then the resistance of the second is what??

Answer 1

Answer:here you go may this help you

Explanation

Power = voltage×current = Voltage×(Voltage/Resistance)

 

Hence if P is power, V is voltage  and R is resistance, then R = V 2 / P

 

hence for first bulb, R1  = V 2 / 75 = R

for second bulb,  R2 = V 2 /150 = (1/2)(V2 / 75) = R/2: