15. For which of the two pairs, the angle of contact is same

(a)  Water and glass; glass and mercury

(b) Pure water and glass; glass and alcohol

(c)   Silver and water; mercury and glass

(d)  Silver and chromium; water and chromium

Ans. (b) Both liquids water and alcohol have same nature (e. wet the solid). Hence angle of contact for both is acute.

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