Q$20.$

$($i$)$ A flat thin vertical electric heating panel, of height $1\mathrm{.}0$ m and width $0\mathrm{.}5$ m $,$ is insulated on one side. If the other surface has a uniform temperature of $\backslash (80^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ),$ calculate the rate of convection heat transfer to the surrounding air at $\backslash (20^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ).(7$ marks$).(130\mathrm{.}9$ W$)$

$($ii$)$ Is the flow regime over the plate laminar or turbulent? Explain. $(3$ marks$).$