Four wires made of same material have different lengths and radii, the wire having more resistance in the following case is

$$\begin{gathered} \mathrm{Resistance} \mathrm{of} \mathrm{a} \mathrm{conductor} \mathrm{is} \mathrm{given} \mathrm{by} \\ \mathrm{R}=\mathrm{\rho }\frac{\mathrm{l}}{\mathrm{A}} \\ \mathrm{as} \mathrm{they} \mathrm{are} \mathrm{of} \mathrm{same} \mathrm{material} \mathrm{resistance} \mathrm{will} \mathrm{be} \mathrm{maximum} \\ \mathrm{which} \mathrm{has} \mathrm{maximum}\frac{\mathrm{l}}{\mathrm{A}} or \frac{l}{\pi r^2}\mathrm{value}. \end{gathered}$$

$$\begin{gathered} \mathrm{compairing}\frac{ \mathrm{l}}{{\mathrm{r}}^2}\mathrm{for} \mathrm{all} \\ 1) \frac{100}{1^2}=100 \\ 2) \frac{50}{2^2}=12.5 \\ 3)\frac{100}{{\left(0.5\right)}^2}=400 \\ 4) \frac{50}{{\left(0.5\right)}^2}=200 \end{gathered}$$