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Que. The accompanying sketch shows the schematic arrangement for measuring the thermal conductivity by the guarded hot plate method. Two similar 1 cm thick specimens receive heat from a 6.5 cm by 6.5 cm guard heater. When the power dissipation by the wattmeter was 15 W, the thermocouples inserted at the hot and cold surfaces indicated temperatures as 325 K and 300 K. What is the thermal conductivity of the test specimen material?
a. 0.81 W/m K
b. 0.71 W/m k
c. 0.61 W/m K
d. 0.51 W/m K
Correct Answer:0.71 W/m k
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