The variation of applied potential and current flowing through a given wire is shown in figure. The length of wire is $31.4 c m$ . The diameter of wire is measured as $2.4 c m$ . The resistivity of the given wire is measured as $x \times 1 0^{- 3} Ω c m$ . The value of $x$ is _____ .
[Take $π = 3.14$ ]

Question

The variation of applied potential and current flowing through a given wire is shown in figure. The length of wire is $31.4 c m$ . The diameter of wire is measured as $2.4 c m$ . The resistivity of the given wire is measured as $x \times 1 0^{- 3} Ω c m$ . The value of $x$ is _____ .

[Take $π = 3.14$ ]

TestHub · Accepted Answer

Since, slope of V−I graph represents the resistance, so $R = tan 4 5^{\circ} = 1Ω$

Now, resistance of wire is given by $R = \frac{ρ L}{A}$

So, resistivity of the wire is $ρ = \frac{A}{R L} = \frac{π r ^{2}}{R L} = \frac{π ( 1. 2 ^{2} \times 1 0 ^{- 4} )}{31.4 \times 1 0 ^{- 2}} = 1.44 \times 1 0^{- 3} Ω m = 144 \times 1 0^{- 3} Ω c m$

Physics - Current Electricity Question with Solution | TestHub

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