The following data pertains to the junction of a thermocouple wire used to measure the temperature of the gas stream.Density = 8500 kg/m3, specific heat = 325 J/kg K, thermal conductivity = 40 W/m K and the heat transfer coefficient between the junction and gas = 215 W/m2 K.If thermocouple junction can be approximated as 1 mm diameter sphere, determine how long it will take for the thermocouple to read 99% of the initial temperature difference

The following data pertains to the junction of a thermocouple wire us

1.	The following data pertains to the junction of a thermocouple wire used to measure the temperature of the gas stream.Density = 8500 kg/m3, specific heat = 325 J/kg K, thermal conductivity = 40 W/m K and the heat transfer coefficient between the junction and gas = 215 W/m2 K.If thermocouple junction can be approximated as 1 mm diameter sphere, determine how long it will take for the thermocouple to read 99% of the initial temperature difference
A.	9.86 seconds
B.	8.86 seconds
C.	7.86 seconds
D.	6.86 seconds
Answer» B. 8.86 seconds

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