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Figure shows a copper rod joined to a st...

Figure shows a copper rod joined to a steel rod. The rods have equal length and equal cross-sectional area. The free end of the copper rod is kept at `0^@C` and that of the steel rod is kept at `100^@C`. Find the temperature `theta` at the junction of the rods. Conductivity of copper
`=390 W//m-^@C` and that of steel `= 46 W//m-^@C`.
.

A

`20.55^@C`

B

`30.55^@C`

C

`10.55^@C`

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
C
`H_(steel) = H_(copper)` (two rods are in series)
`:. ((TD)_S/(l//KA)_S) = ((TD)_C/(l//KA)_C)`
or `K_S (TD)_S = K_C (TD)_C`
or ` 46(100-theta) = 390 (theta-0)`
Solving we get, `theta = 10.6^@C`.
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Knowledge Check

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