To measure thermal conductivity, two similar 1-cm-thick specimens are placed in an apparatus shown in the accompanying

Question:

To measure thermal conductivity, two similar 1-cm-thick specimens are placed in an apparatus shown in the accompanying sketch. Electric current is supplied to the 6-cm by 6-cm guarded heater, and a wattmeter shows that the power dissipation is 10 watts (W). Thermocouples attached to the warmer and to the cooler surfaces show temperatures of 322 and 300 K, respectively. Calculate the thermal conductivity of the material at the mean temperature in Btu/(h ft?F) and W/(m K).GIVENThermal conductivity measurement apparatus with two samples as shownSample thickness (L) = 1 cm = 0.01 cmArea = 6 cm × 6 cm = 36 cm2 = 0.0036 m2Power dissipation rate of the heater (qh) = 10WSurface temperaturesThot = 322 K and Tcold = 300 KASSUMPTIONSOne dimensional, steady state conductionNo heat loss from the edges of theapparatus