[amp_mcq option1=”1.5″ option2=”2.7″ option3=”4.2″ option4=”7.8″ correct=”option2″]
The correct answer is B. 2.7.
Specific gravity is the ratio of the density of a substance to the density of a standard substance. The standard substance is usually water, which has a density of 1 gram per cubic centimeter.
Aluminium has a density of 2.7 grams per cubic centimeter. This means that aluminium is 2.7 times as dense as water.
Option A is incorrect because 1.5 is not the specific gravity of aluminium.
Option C is incorrect because 4.2 is not the specific gravity of aluminium.
Option D is incorrect because 7.8 is not the specific gravity of aluminium.