Short & Long Questions: The Hydrosphere | Window on the Word Class 7: Solutions, Notes & Worksheets PDF Download

Short Answer Questions

Q1: What is the hydrosphere?
Ans: The hydrosphere is all the water on, below, and above the Earth's surface.

Q2: What percentage of Earth's surface is covered by water?
Ans: About 71% of Earth's surface is covered by water.

Q3: Why is ocean water unsuitable for drinking?
Ans: Ocean water is highly saline and contains a large amount of salt, making it unfit for drinking.

Q4: What are the three main processes in the water cycle?
Ans: The three main processes in the water cycle are evaporation, condensation, and precipitation.

Q5: What causes waves in the ocean?
Ans: Waves are primarily caused by strong winds blowing across the ocean's surface.

Q6: What are spring tides, and when do they occur?
Ans: Spring tides are tides with higher high tides and lower low tides. They occur during Full Moon and New Moon when the Moon and Sun align.

Q7: What are neap tides, and when do they occur?
Ans: Neap tides have lower high tides and higher low tides. They occur when the Moon and Sun are at right angles during the quarter phase.

Q8: What is the purpose of Tsunami Warning Systems?
Ans: Tsunami Warning Systems provide timely alerts to coastal areas in the event of tsunamis, allowing people to evacuate and save lives.

Q9: How do ocean currents influence the climate in different parts of the world?
Ans: Ocean currents help regulate the temperature in various regions. For example, the North Atlantic Current ensures milder climate in northern Europe.

Q10: What can happen when warm and cold ocean currents meet?
Ans: When warm and cold currents meet, it can create excellent fishing grounds due to the upsurge of nutrients, but it may also lead to heavy fog, disrupting marine vessel movement.

Long Answer Questions

Q1: Explain the water cycle in detail.
Ans: The water cycle is a continuous process where water changes its form. It starts with evaporation, where water is heated by the Sun and turns into water vapor. Then, condensation occurs as water vapor cools and forms clouds. Finally, precipitation happens, returning water to the Earth as rain, snow, hail, or sleet.

Q2: Describe the factors that influence ocean currents and provide examples of warm and cold currents.
Ans: Ocean currents are influenced by factors like temperature, Earth's rotation, winds, density, salinity, and coastline shape. Warm currents, such as the North Atlantic Current, flow from the equator towards the poles, while cold currents, like the Labrador Ocean Current, flow from higher latitudes to lower latitudes.

Q3: What are tides, and how do they form?
Ans: Tides are the periodic rise and fall of ocean waters. They form due to the gravitational pull of the Moon and the Sun on the Earth. The side of the Earth facing the Moon experiences high tide, while the side opposite the Moon also bulges, creating a second high tide.

Q4: Explain the importance of tides for various purposes, including navigation and fishing.
Ans: Tides are essential for sailors to enter and leave harbors, as they enter at high tide and leave during low tide. They are also used for electricity generation and help fishermen catch more fish, as the mixing of warm and cold currents at tidal zones promotes the growth of phytoplankton, attracting fish and marine mammals.

Q5: Discuss the issues facing the quality and distribution of water on Earth and suggest methods for water conservation.
Ans: Various human activities, such as water pollution, urban expansion, deforestation, and excessive freshwater usage, have led to water scarcity. To conserve water, measures like rainwater harvesting, pollution prevention, water reuse, and fixing leaks can be implemented.