Four equal resistors are connected in series across a source of emf. Together they dissipate 5 W of power. If the same four equal resistors are connected in parallel across the same source of emf then the total power dissipated will be
Answer & explanation
Correct answer: option 3
In Series $P = \frac{V^2}{4R}$
In Parallel $P' = \frac{4V^2}{R} $
$ \frac{P'}{P} = 16 $
$ \Rightarrow P'= 16P = 80W$