The angle of contact at the interface of water glass is `0^(@)` ethylalcohol-glass is `0^(@)` mercury glass is `140^(@)` and methyliodide-glass is `30^(@)` A glass capillary is put in a through containing one of these four liquids. It is observed that the meniscus is convex. The liquid in the through is

Options

A. Water
B. Ethylalcohol
C. Mercury
D. Methyliodide

Answer

C

Explanation

According to the question, the observed meniscus is convex which is only possible when angle of contact is obtuse.
Hence, the combination will be of mercury-glass `(140^@)`