MCQ Detailed View

An iceberg floats in seawater because its density is lower than that of water. Ice has a density of about 0.92 g/cm³, while seawater has a slightly higher density, approximately 1.025 g/cm³ due to dissolved salts. According to Archimedes' principle, the fraction of a floating object submerged in a fluid is equal to the ratio of its density to the fluid’s density.

For ice in seawater:
Fraction submerged = Density of ice ÷ Density of seawater
= 0.92 ÷ 1.025 ≈ 0.9 (about 90% below water)

This means only about 10% (one-tenth) of the iceberg's total mass remains above the water surface, while the majority stays submerged. This is why large parts of icebergs remain hidden under water, making them dangerous for ships as most of their mass is not visible.

Other options (one-fifth, one-fourth, one-third) overestimate the amount above water. Scientific measurements consistently show that roughly 1/10th of an iceberg is visible, while 9/10ths are submerged due to buoyancy and density differences.

Thus, the correct answer is Option 1: One tenth.