Current Electricity Ques 70 — JEE PYQ Chapterwise

Answer:

Correct Answer: 70.(a)

Solution:

Formula:

Electrical Power:

70. $P=i^{2} R$

Current is same, so $P \propto R$.

In the first case it is $3 r$, in second case it is $\frac{2}{3} r$, in third case it is $\frac{r}{3}$ and in fourth case the net resistance is $\frac{3 r}{2}$.

$ \begin{array}{rlrl} & R _{\text {III }}<R _{\text {II }}<R _{\text {IV }}<R _{II} \\ \therefore & P _{\text {III }}<P _{\text {II }}<P _{\text {IV }}<P _I \end{array} $