The resistance of a wire of uniform diameter d and length L is R. The resistance of another wire of the same material but diameter

Q: The resistance of a wire of uniform diameter $d$ and length $L$ is $R$. The resistance of another wire of the same material but diameter $2d$ and length $4L$ will be

b (b) $R \propto \frac{l}{A} \propto \frac{l}{{{d^2}}}$ $\Rightarrow $ $\frac{{{R_1}}}{{{R_2}}} = \frac{{{l_1}}}{{{l_2}}} \times \,{\left( {\frac{{{d_2}}}{{{d_1}}}} \right)^2} = \frac{L}{{4L}}\,{\left( {\frac{{2d}}{d}} \right)^2} = 1$ $\Rightarrow $ $R_2 = R_1 = R.$

SECTION - A [PHYSICS - MCQ]

GSEB - English Medium

The resistance of a wire of uniform diameter $d$ and length $L$ is $R$. The resistance of another wire of the same material but diameter $2d$ and length $4L$ will be

A$2R$
B$R$
C$R/2$
D$R/4$

Easy

STD 11 Science
NEET
STD 12 - 3. current electricity
Physics

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