Question

If negligibly small current is passed though a wire of length $15 \, m$ and resistance of $5\, \Omega$, having uniform cross section of $6 \times 10^{-7}\, m ^2$, then coefficient of resistivity of material is

• A. $1 \times 10^{-7} \, \Omega- m$
• B. $2 \times 10^{-7} \, \Omega- m$
• C. $3 \times 10^{-7}\, \Omega- m$
• D. $4 \times 10^{-7} \, \Omega- m$

Answer 1

Answer: (B)

(Hint $\Rightarrow \rho=\frac{\text { R.A }}{\ell}=$ Coefficient of resistivity)