Answer:
is closest to 100*C temperature at the aluminum-copper junction
Explanation:
The expression for calculating the resistance of each rod is given by
[tex]R =\frac{ L}{ kA}[/tex]
Now; for Aluminium
[tex]R_{al} =\frac{ 0.20 }{ 205*0.0004}[/tex]
[tex]R_{al}[/tex] = 2.439
For Copper
[tex]R_{Cu}=\frac{0.70}{385*0.0004}[/tex]
[tex]R_{Cu} = 4.545[/tex]
Total Resistance [tex]R = R_{al} + R_{Cu}[/tex]
= 2.439 + 4.545
= 6.9845
Total temperature difference = 230*C + 30*C
= 200 *C
The Total rate of heat flow is then determined which is = [tex]\frac{ total \ temp \ difference}{total \ resistance }[/tex]
=[tex]\frac{200}{ 6.9845 }[/tex]
= 28.635 Watts
However. the temperature difference across the aluminium = Heat flow × Resistance of aluminium
= 28.635 × 2.349
= 69.84 *C
Finally. for as much as one end of the aluminium is = 30 *C , the other end is;
=30*C + 69.84*C
= 99.84 *C
which is closest to 100*C temperature at the aluminum-copper junction
