A mercury thermometer with bulb idealized as a sphere of 1 mm radius is used for measuring the temperature of fluid whose temperature is varying at a fast rate. For mercuryk = 10 W/m Kα = 0.00005 m²/sh = 10 W/m² KIf the time for the temperature change of the fluid is 3 second, what should be the radius of thermocouple to read the temperature of the fluid?For the thermocouple materialk = 100 W/m Kα = 0.0012 m²/sh = 18 W/m² K

A mercury thermometer with bulb idealized as a sphere of 1 mm radius i

1.	A mercury thermometer with bulb idealized as a sphere of 1 mm radius is used for measuring the temperature of fluid whose temperature is varying at a fast rate. For mercuryk = 10 W/m Kα = 0.00005 m²/sh = 10 W/m² KIf the time for the temperature change of the fluid is 3 second, what should be the radius of thermocouple to read the temperature of the fluid?For the thermocouple materialk = 100 W/m Kα = 0.0012 m²/sh = 18 W/m² K
A.	.864 mm
B.	.764 mm
C.	.664 mm
D.	.564 mm
Answer» B. .764 mm