Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Alcohol rather than mercury is used in a thermometer to measure a temperature of - 60° C.
Reason (R) : Alcohol has a lower freezing point than mercury.
In the light of the above statements, choose the most appropriate answer from the options given below :
Answer & explanation
Correct answer: option 1
(I). (A) is correct: We do use alcohol in thermometers to measure temperatures below -60°C.
(II). (R) is also correct: The reason why we use alcohol in thermometers to measure temperatures below -60°C is that alcohol has a lower freezing point than mercury.
(III). (R) is the correct explanation of (A): The fact that alcohol has a lower freezing point than mercury is the reason why we use alcohol in thermometers to measure temperatures below -60°C.
Thus, both statements are correct and the reason stated in (R) is the correct explanation for why we use alcohol in thermometers to measure temperatures below -60°C.