JEE Main 2021 — Current Electricity Question with Solution
From: JEE Main 2021 (Online) 1st September Evening Shift
Question
A uniform heating wire of resistance 36 is connected across a potential difference of 240 V. The wire is then cut into half and potential difference of 240V is applied across each half separately. The ratio of power dissipation in first case to the total power dissipation in the second case would be 1 : x, where x is ____________
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Show full solutionCorrect answer: 4
Correct answer
4
Step-by-step explanation
For Case I,
The potential difference of the uniform wire, V = 240 V
The resistance of the uniform wire, R1 = 36
The power dissipation in the first case,
For Case II,
The resistance of each half,
Thus, the ratio of the total power dissipation in the first case to the second case
Comparing with,
The value of the x = 4.
The potential difference of the uniform wire, V = 240 V
The resistance of the uniform wire, R1 = 36
The power dissipation in the first case,
For Case II,
The resistance of each half,
Thus, the ratio of the total power dissipation in the first case to the second case
Comparing with,
The value of the x = 4.
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This is a previous-year question from JEE Main 2021, covering the Current Electricity chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.