Q$-13)$ Consider $60W,240V$ incandescent light bulb. The Tungsten filament is $0\mathrm{.}381$ lm long and $33m$ in diameter. Resistivity at room temperature $(20C)$ is $5\mathrm{.}51{10}^{-8}.$ Given that the resistivity of tungsten $($W$)$ varies $T^{1\mathrm{.}72},$ estimate the temperature of the bulb at operated voltage. $($Hint: $={}_0**(\frac{T}{T_0}{)}^n$;$,=\frac{R**A}{l},$;$A=**r^2)(5$ Pts$.)$