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 $x \times 10^{- 3} Ω cm$ . 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 $31.4 cm$ . The diameter of wire is measured as $2.4 cm$ . The resistivity of the given wire is measured as $x \times 10^{- 3} Ω cm$ . The value of $x$ is _____ .

[Take $π = 3.14$ ]

TestHub · Accepted Answer

Since, slope of V−I graph represents the resistance, so $R = \tan 45 ° = 1 Ω$

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

So, resistivity of the wire is $ρ = \frac{A}{R L} = \frac{π r^{2}}{R L} = \frac{π (1 . 2^{2} \times 10^{- 4})}{31.4 \times 10^{- 2}} = 1.44 \times 10^{- 3} Ω m = 144 \times 10^{- 3} Ω cm$

Physics - Current Electricity Question with Solution | TestHub

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