The question asks for the approximate percentage of the Earth's surface covered by water. This is a fundamental geographical fact often tested in general knowledge sections of competitive exams. We need to recall the widely accepted scientific figure.
Correct Option: D) About 71% (roughly three-fourths)
This option accurately represents the proportion of the Earth's surface covered by water. The Earth's surface is approximately 71% water and 29% land. This is a well-established fact in geography and environmental science.
The question asks why Earth is called the 'Blue Planet'. This nickname is derived from its appearance when viewed from space. We need to identify the primary reason for this visual characteristic.
A) Most of its surface is covered by oceans, which appear blue from space. This statement accurately explains why Earth is called the 'Blue Planet'. Approximately 71% of Earth's surface is covered by water, and the oceans reflect blue light, making the planet appear predominantly blue from space.
This question tests general geographical knowledge about the distribution of land and water across the Earth's hemispheres. We need to recall the major continents and oceans and their general locations relative to the Equator and Prime Meridian.
Correct Option: C) The Northern Hemisphere has more land than the Southern Hemisphere; the Southern Hemisphere has far more water than land
The question asks about the most widely used model for the number of continents. Different models exist globally, but one is predominantly taught and recognized in many parts of the world, including India.
Correct Option: C) Seven is the correct answer because the seven-continent model is the most widely accepted and taught model in many parts of the world.
The question asks to identify the largest continent by land area. This requires knowledge of the relative sizes of the Earth's continents.
Correct Option: B) Asia (~44.58 million sq. km)
Asia is the largest continent in the world by land area, covering approximately \(44.58 \times 10^6 \, \text{km}^2\), which is about 30% of the Earth's total land area and 8.7% of the Earth's total surface area. It is also the most populous continent.
The question asks to identify the smallest continent by area. This requires knowledge of the approximate areas of the world's continents.
Correct Option: D) Australia (approximately 8.5 million sq. km) is the smallest continent in the world by area. Its area is approximately \(8.5 \text{ million sq. km}\), which is significantly smaller than any other continent.