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

Moderate

A

when the wire is connected to the battery directly
B

when the wire is divided into two parts and both the parts are connected to the battery in parallel
C

when the wire is divided into four parts and all the four parts are connected to the battery in parallel
D

when only half of the wire is connected to the battery

Solution

let .R be the resistance of the wire.
(a) $H_{1} = \frac{V^{2} t}{R}$
(b) Resistance of each part will be R/2. When they are connected in parallel, the resistance will be R/4. Hence
$H_{2} = \frac{4 V^{2} t}{R}$
(c) In case of four wires connected in parallel, the resistance will be .R/16
$∴ H_{3} = \frac{16 V^{2} t}{R}$
(d) $H_{4} = \frac{V^{2} t}{(R / 2)} = \frac{2 V^{2} \cdot t}{R}$
Hence largest amount of heat will be generated in' case of four parts connected in parallel

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

SCAN ME