JEE Main 2022 · 29 Jun · Shift 1 · Physics Q55

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PhysicsInteger+4 / -1Question 55 of 90

The variation of applied potential and current flowing through a given wire is shown in figure. The length of wire is 31.4 cm. The diameter of wire is measured as 2.4 cm. The resistivity of the given wire is measured as $x\times10^{-3}$ $\Omega$ cm. The value of $x$ is ______.

[Take $\pi=3.14$ ]

Potential (volt) against I (A): a straight line through the origin at 45° to the I axis.

Your answer

Answer and worked solution

Official answer: 144

Resistance. The 45° line gives $R=1$ Ω.

Resistivity. $\rho=\dfrac{RA}L=\dfrac{3.14\times1.2^2}{31.4}=0.144$ Ω cm $=144\times10^{-3}$ Ω cm.

Answer: 144

Topics:Ohm's law and resistivity

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JEE Main 2022 · 29 Jun · Shift 1, Physics question 55