A clinical mercury thermometer is placed first in a cup of hot water and later in a…
PHYSICS · Subjective · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics
Problem
A clinical mercury thermometer is placed first in a cup of hot water and later in a cup of warm water.
(i) Describe qualitatively how the mercury meniscus moves in each case until it reaches a steady reading.
(ii) Explain why the thermometer finally shows a constant temperature even though heat continues to flow between the mercury and its glass envelope.
(iii) Comment on whether the quantity of mercury inside the thermometer affects the final reading obtained for the temperature of the water. Give reason.