Question

You are given a resistance wire of length 50 cm and a battery of negligible resistance. In which of the following cases is largest amount of heat generated

• A. When the wire is connected to the battery directly
• B. When the wire is divided into two parts and both the parts connected to the battery in parallel
• C. When the wire is divided into four parts and all the four connected to the battery in parallel
• D. When only half the wire is connected to the battery

Answer 1

Answer: (C)

When the wire is divided into four parts and all the four connected to the battery in parallel

Answer 2

In this case, $P = \frac{V^{2}}{R}$or $P \propto \frac{1}{R}$and$R$will be minimum, when divided four parts are joints in parallel to the battery.