Answer:
778.4°C
Explanation:
I = 700
R = 6x10⁻⁴
we first calculate the rate of heat that is being transferred by the current
q = I²R
q = 700²(6x10⁻⁴)
= 490000x0.0006
= 294 W/M
we calculate the surface temperature
Ts = T∞ + [tex]\frac{q}{h\pi Di}[/tex]
Ts = [tex]30+\frac{294}{25*\frac{22}{7}*\frac{5}{1000} }[/tex]
[tex]Ts=30+\frac{294}{0.3928} \\[/tex]
[tex]Ts =30+748.4\\Ts = 778.4[/tex]
The surface temperature is therefore 778.4°C if the cable is bare
