Test: Water - UPSC MCQ

The Gulf Stream is a warm ocean current. Here are some key points:

• It originates in the Gulf of Mexico.
• Flows along the eastern coast of the United States.
• Helps moderate the climate of nearby regions by transporting warm water.

The average salinity of the ocean is approximately 35 parts per thousand (ppt). This means there are about 35 grams of dissolved salts in every kilogram of seawater.

This value can vary slightly depending on factors such as:

• Location
• Environmental conditions

However, 35 ppt is widely accepted as the global average for ocean water salinity.

The Labrador Current is known as a cold ocean current. Here are some important points about it:

• It flows southward along the coast of Canada and into the North Atlantic Ocean.
• The cold waters significantly influence the climate of the regions it passes.
• This current plays a crucial role in the marine ecosystem by supporting diverse marine life.

About 97.3% of Earth's water is found in the oceans and other saline (salt) water bodies. The remaining 2.7% is freshwater, which is mostly stored in glaciers, ice caps, and groundwater.

So:

• Oceans: ~97.3%
• Freshwater: ~2.7% (including glaciers, rivers, lakes, groundwater, etc.)

The Dead Sea is renowned for having the highest salinity among the given options, with a salt concentration of approximately 33.7%. This extreme salinity significantly increases the water's density, allowing individuals to float effortlessly on its surface due to the buoyant force exerted by the dense water.

Clouds form through the process of condensation, which involves the following steps:

• Water vapor in the atmosphere cools.
• This cooled water vapor transforms into tiny droplets or ice crystals.
• The accumulation of these droplets or crystals creates visible clouds.

The correct answer is: B: Rivers, ponds, springs, and glaciers

The primary sources of fresh water on Earth include:

• Rivers and ponds (surface water)
• Springs (groundwater emerging to the surface)
• Glaciers (frozen freshwater reserves)

These sources collectively provide the majority of accessible freshwater for human use, agriculture, and ecosystems.