JEE Main 2021 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 26 February 2021, Shift 2, Physics Q20

Question 20 of 90 in this shift, Physics question 20 of 30, Section A.

A wire of 1

\Omega

has a length of 1 m. It is stretched till its length increases by 25%. The percentage change in resistance to the nearest integer is :

(1)76%
(2)56%Official answer
(3)25%
(4)12.5%

Official answer

Option 2

NTA final key.

Chapter: Current Electricity
Topic: Ohm's Law and Resistance
Idea tested: Resistance of Stretched Wires

Same idea in other shifts

Asked 8× in all

4 Apr 2024, Shift 2 · Q55Two wires $A$ and $B$ are made up of the same material and have the same mass. Wire $A$ has radius of 2.0 mm and wire $B$ has radius of…MediumNumerical value
6 Apr 2024, Shift 1 · Q58A wire of resistance $R$ and radius $r$ is stretched till its radius became $r/2$ . If new resistance of the stretched wire is $x\,R$ , then…EasyNumerical value
12 Apr 2023, Shift 1 · Q42A wire of resistance 160 $\Omega$ is melted and drawn in a wire of one-fourth of its length. The new resistance of the wire will beEasySingle correct
28 Jul 2022, Shift 1 · Q41A wire of resistance $R_1$ is drawn out so that its length is increased by twice of its original length. The ratio of new resistance to…EasySingle correct
29 Jul 2022, Shift 2 · Q35A 1 m long wire is broken into two unequal parts X and Y. The X part of the wire is streched into another wire W. Length of W is twice the…MediumSingle correct
25 Jun 2022, Shift 2 · Q58The length of a given cylindrical wire is increased to double of its original length. The percentage increase in the resistance of the…EasyNumerical value
3 Aug 2021, Shift 1 · Q23The length of a wire is increased by 20% by stretching. The percentage increase in resistance of wire will be ______.EasyNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.