Discussion Forum



1)

In the following question, there are two statements labelled as Assertion (A) and 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


A) Both A and R are true and R is the correct explanation of A

B) Both A and, R are true but R is not the correct explanation of A.

C) A is true but R is false.

D) A is false but R is true

E) Both A and R are false

Answer:

Option A

Explanation:

Mercury freezes at - 39°C while alcohol freezes at a point far below - 100°C  So , alcohol is used to measure lower temperatures. Similarly, mercury boils at 357°C, while alcohol boils at 78°c. So, mercury is used to measure high temperatures.