An immersion heater with electrical resistance $7 \mathrm{\Omega }$ is immersed in 0.1 kg of water at $\mathrm{20 }\mathrm{℃}$ for 3 min. If the flow of current is 4 A, what is the final temperature of the water assuming whole of  heat produced is consumed in water. $\left({\mathrm{S}\mathrm{p}\mathrm{e}\mathrm{c}\mathrm{i}\mathrm{f}\mathrm{i}\mathrm{c}\mathrm{ }\mathrm{h}\mathrm{e}\mathrm{a}\mathrm{t}\mathrm{ }\mathrm{c}\mathrm{a}\mathrm{p}\mathrm{a}\mathrm{c}\mathrm{i}\mathrm{t}\mathrm{y}\mathrm{ }\mathrm{o}\mathrm{f}\mathrm{ }\mathrm{w}\mathrm{a}\mathrm{t}\mathrm{e}\mathrm{r}=4.2\times {10}^3 \mathrm{J }\mathrm{k}\mathrm{g}}^{-1}{\mathrm{K}}^{-1}\right)$