Question

The specific gravity of magnesium is __________

(a) 1.8

(b) 7.9

(c) 2.7

(d) 13.8

This question was posed to me in a national level competition.

Origin of the question is Magnesium and its Alloys-1 topic in section Magnesium Alloys of Aerospace Materials & Processes

Answer 1

The correct choice is (a) 1.8

For explanation I would say: The specific gravity of an object refers to the ratio of the density of that object to the density of a reference object. The specific gravity of magnesium is 1.8. The specific gravity of aluminium is 2.7 and steel is 7.9.