JEE Main 2018PhysicsCurrent ElectricityMediumMCQ

JEE Main 2018 — Current Electricity Question with Solution

JEE Main 2018 (16 Apr Online)

Question

A heating element has a resistance of 100 Ω at room temperature. When it is connected to a supply of 220 V, a steady current of 2 A passes in it and temperature is 500 oC more than the room temperature. The temperature coefficient of resistance of the heating element is

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Show full solutionCorrect option: B
Correct answer
B2 ×10-4  oC-1

Step-by-step explanation

Resistance of heating element after temperature increases by 500 oC=2202=110 Ω (from Ohm's law). The new resistance is related to the temperature coefficient of the heating element as 110=100 (1+α500)

α=10100 ×500⇒α=2 ×10-4 °C-1

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About this question

This is a previous-year question from JEE Main 2018, 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.