1–28C

1–28C Consider an alcohol and a mercury thermometer
that read exactly 0°C at the ice point and 100°C at the steam
point. The distance between the two points is divided into
100 equal parts in both thermometers. Do you think these
thermometers will give exactly the same reading at a temperature of, say, 60°C? Explain.
ANS
1-28C  Probably, butnotnecessarily. The operation of these two thermometers isbased on the thermal
expansion of a fluid. If the thermalexpansion coefficientsof both fluids varylinearlywithtemperature,
then both fluids will expandat the samerate with temperature, andboththermometers will always give
identical readings. Otherwise, the two readings maydeviate.