water is a standard fixed point in modern thermometry. Why ? What is wrong in taking the melting point of ice and the boiling point of water as standard fixed points (as was originally done in the Celsius scale) ? (b) There were two fixed points in the original Celsius scale as mentioned above which were assigned the number ° C and ° C respectively.
On the absolute scale, one of the fixed points is the triple-point of water, which on the Kelvin absolute scale is assigned the number . K. What is the other fixed point on this (Kelvin) scale ? (c) The absolute temperature (Kelvin scale) T is related to the temperature t c on the Celsius scale by t c = T – .
Why do we have . in this relation, and not . ? (d) What is the temperature of the triple-point of water on an absolute scale whose unit interval size is equal to that of the Fahrenheit scale ?
. Two ideal gas thermometers A and B use oxygen and hydrogen respectively. The following observations are made : Temperature Pressure Pressure thermometer A thermometer B Triple-point of water . × Pa .
× Pa Normal melting point . × Pa . × Pa of sulphur (a) What is the absolute temperature of normal melting point of sulphur as read by thermometers A and B ? (b) What do you think is the reason behind the slight difference in answers of thermometers A and B ?
(The thermometers are not faulty). What further procedure is needed in the experiment to reduce the discrepancy between the two readings ? . A steel tape 1m long is correctly calibrated for a temperature of .
° C. The length of a steel rod measured by this tape is found to be . cm on a hot day when the temperature is . ° C.
What is the actual length of the steel rod on that day ? What is the length of the same steel rod