Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A metal rod consumes power $P$ on passing current. If it is cut into two half and joined in parallel, it will consume power
PhysicsCurrent ElectricityAIIMSAIIMS 2001
Options:
  • A $P$
  • B $2 P$
  • C $4 P$
  • D $P / 4$.
Solution:
2016 Upvotes Verified Answer
The correct answer is: $4 P$
Let the resistance of the rod be $R$. If the rod is divided into two equal parts, then each part of the rod will have a resistance of $R / 2$. Now these two parts of the rod are connected in parallel and a voltage $V$ is applied across them. Hence the total power consumed is
$$
P^{\prime}=\frac{V^2}{R / 2}+\frac{V^2}{R / 2}=4 \frac{V^2}{R}=4 P \text { where }
$$
$P=\frac{V^2}{R}$ is the power consumed by the original rod when voltage $V$ is applied across it.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.