Water quiz

The average salinity of ocean water is about:

Most of the Earth's water is found in:

Tides are caused mainly by the gravitational pull of the:

Spring tides occur on:

The Gulf Stream is a:

The Dead Sea has a salinity of about:

Tsunamis are caused by:

The Labrador Current is a:

The rise of ocean water towards the coast twice a day is called:

World Water Day is observed on:

Why is ocean water salty? (2 marks)

How are waves formed? (2 marks)

What are neap tides? (2 marks)

Why can people float easily in the Dead Sea? (2 marks)

How are tides useful for fishing and navigation? (2 marks)

How do warm ocean currents affect coastal climate? (2 marks)

Why is fresh water called a precious resource? (2 marks)

How can tides be used to produce electricity? (2 marks)

What is the difference between a wave and a current? (2 marks)

Name two causes of water shortage in cities. (2 marks)

Sea water has 35 g of salt per litre. How much salt can be obtained by evaporating 500 litres of sea water? Give your answer in kg. (3 marks)

High tide at a place occurred at 6:00 am. Assuming tides every 12 hours 25 minutes, find the times of the next two high tides. (3 marks)

Of the Earth's water, 97.3 percent is in oceans, 2.0 percent in ice caps and 0.68 percent is groundwater. Find the total percentage of these three and the percentage left for lakes, rivers and the atmosphere. (3 marks)

The 2004 tsunami waves travelled across the Indian Ocean at about 700 km/h. How long would they take to cover 2,100 km? (3 marks)

A city needs 600 million litres of water a day but receives only 450 million litres. Find the shortage and the percentage of demand that is met. (3 marks)

Read the passage and answer the questions. On 26 December 2004, an earthquake off the coast of Sumatra in Indonesia caused a tsunami. Waves hit India's coast, including the Andaman and Nicobar Islands and Tamil Nadu. (i) What caused the tsunami? (ii) Why did the waves reach far-off countries? (iii) What lesson did India learn? (5 marks)

Read the passage and answer the questions. Fishermen at a coastal village plan their trips according to the timing of tides. Ships wait for high tide to enter the harbour. (i) What are tides? (ii) Why do ships wait for high tide? (iii) How do tides help fishermen? (5 marks)

Read the passage and answer the questions. Near Newfoundland, the warm Gulf Stream meets the cold Labrador Current. The area has thick fog and is one of the richest fishing grounds. (i) Why does fog form there? (ii) Why are fish plentiful? (iii) Name one other such region. (5 marks)

Read the passage and answer the questions. Salt pans along the coast of Gujarat produce a large share of India's salt. Sea water is let into shallow pans and left in the sun. (i) What process produces salt? (ii) Why is Gujarat suitable? (iii) What is the main salt in sea water? (5 marks)

Read the passage and answer the questions. In a village, the pond has dried up, wells are deeper and women walk long distances for water. Most rain runs off quickly. (i) Why has the water table fallen? (ii) How can rainwater be harvested? (iii) Suggest two more measures to conserve water. (5 marks)

Draw and explain the water cycle. (6 marks)

Explain the three movements of ocean water: waves, tides and currents. (6 marks)

Explain the causes and types of tides with diagrams of spring and neap tides. (6 marks)

Explain the distribution of water on Earth and draw a pie chart: oceans 97.3 percent, ice caps 2.0 percent, others 0.7 percent. (6 marks)

Explain the importance of ocean currents and mark two warm and two cold currents on an outline world map. (6 marks)