**R/4**- R/2
- R
- 4R

## Two wires of the same length and material have a diameter of wire A twice that of wire B. If the resistance of wire B is R then the resistance of wire A is

Two wires of the same length and material have a diameter of wire A twice that of wire B. If the resistance of wire B is R then the resistance of wire A is **R/4.**

- the resistance of the wire is given by
**R = ρ*L/A** - because both wires have the same length and the same material so the value of
**ρ**same for both wires. - The cross-sectional area of the wire is
**A = πr**^{2} **first wire:**R_{A}= ρ*L/πr^{2}= ρ*L/4πD^{2}/4 because r = D/2 (put D = 2D because wire A have double diameter)**second wire:**R_{B}= ρ*L/πr^{2}= ρ*L/πD^{2}/4 because r = D/2- divide R
_{A}and R_{B}i-e R_{A}/R_{B}= 1/4 **R**_{A}= R_{B}/4

This question is about MSc Electricity and Magnetism MCQs. This is the previous year’s question about the competitive exams.

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