Direction: Choose the correct alternative from the following options as given below for the Assertion (A) and Reason (R) given in each of the questions.
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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.
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- if both A and R are true and R is the correct explanation of A
- if both A and R are true and R is not the correct explanation of A
- if A is true but R is false
- if A is true but R is true
Correct Option: A
We know that, 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 temperature.
