When length becomes 3L, area becomes A/3 (volume constant). Resistance ( R = \rho \fracLA ) Initial: ( 12 = \rho \fracLA ) New: ( R' = \rho \frac3LA/3 = \rho \frac9LA = 9 \times 12 = 108\ \Omega ) Answer: 108 Ω

A wire of resistance 12 Ω is stretched to thrice its original length. Its new resistance is: