Two resistors when connected in series to a 120-V line use one-fourth the power that is used when they are connected in parallel. If one resistor is 4.8 kohms. what is the resistance of the other?

1 answer

Power for resistors in series
= V²/(R1+R2)

Power for resistors in parallel
= V²/(1/(1/R1+1/R2))
= V²*(1/R1+1/R2)

Solve for R2.