Water Pollution

Q.

How do industries cause water pollution?

Q.

Name Any Four Activities Which You Can Do Without Water

Q.

Continuous addition of sugars in ‘fed batch’ fermentation is done to

1. Purify enzymes

2. Produce methane

3. Obtain antibiotics

4. Degrade sewage

Q.

Name three water borne diseases.

Q.

Explain why, hot water released by power plants and industries is considered a pollutant.

Q.

Name any four pollutants which cause water pollution. State any three ways of controlling water pollution.

Q. BOD test or Biological Oxygen Demand test is carried out for measuring –

1. Water pollution
2. Air pollution
3. Noise pollution
4. Soil pollution

Q. Which of the following is not used in wastewater treatment?

1. Chlorine
2. Biogas
3. Air
4. Ozone

Q.

Explain the harmful effects associated with the disposal of plastics

Q.

Which of the following is used as a disinfectant?

1. Sugar charcoal

2. Wood charcoal

3. Animal charcoal

Q. Contamination is:

1. addition of harmful substances

2. process of adding vital minerals

3. process of removing harmful substances

4. process of killing germs and microorganisms

Q. Fertilizers are good for crops but cause pollution. Explain

Q.

What are the main causes of water pollution ? How can it be controlled ?

Q.

At many places the wastewater containing human excreta from homes and carried in big underground pipes is dumped into a river as such which pollutes the riverwater.

(a) What is the common name of such wastewater?

(b) Name five types of harmful organisms contained in it.

(c) Name any five human diseases caused by drinking river water contaminated with such wastewater.

Q.

Which of the following is not a hard water?

1. Water containing dil. HCl

2. None of these

3. Water containing CaCl₂

4. Water containing MgSO₄

Q.

How can you control water pollution?

Q.

What are the natural cleansing agents of water?

Q.

Match the items given in column I with one or more items given in column II :

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{(i) prevents photosynthesis}& \text{(a) Sewage dumped in river}\\ \text{(ii) Damage ozone layer}& \text{(b) Excess fertiliser in fields}\\ \text{(iii) Produce acid rain}& \text{(c) Carbon dioxide in air}\\ \text{(iv) Kill fish by deoxygenating water}& \text{(d) Dust in air}\\ \text{(v) Causes water borne diseases}& \text{(e) CFCs}\\ \text{(vi) Leads to global warming}& \text{(f) Sulphur dioxide in air}\end{array}$

Q. How does dumping sewage into the water bodies affect the fishes in it?

1. It increases $O_2$ competition among the fishes
2. The nitrogen content of the water decreases.
3. Fish and other aquatic animals die due to the bad odour
4. It replaces food material of fishes

Q.

What is Thermal Pollution?

Q.

Lindane and gammaxene are example of:

1. Air pollutants

2. Pesticides

3. Fungicides

4. Aerosol spray propellants

Q.

The use of excessive fertilisers in the fields leads to the deficiency of an important substance in the water of a nearby lake. Name the substance.

Q. Water which is fit or safe for drinking is known as water.

1. sea
2. potable
3. sewage

Q.

Which of the following is/are the uses of fresh water?

1. Drinking

2. Bathing

3. Cooking

4. All of the above

Q.

Pesticides get washed off by rain into water sources and make ground water germ free.

1. True

2. False

Q. Statement: Eutrophication is nutrient enrichment of water bodies due to human activities.​
Reason: The prime contaminants from sewage and industrial effluents are nitrates and phosphates, which overstimulate the growth of algae.​

1. Both the statement and the reason are correct, and the reason is not the correct explanation for the statement.
2. Both the statement and the reason are correct, and the reason is the correct explanation for the statement.
3. Both the statement and the reason are incorrect.
4. The statement is correct, but the reason is incorrect.

Q. Write any four methods of controlling water pollution.

Q.

Which of the following can be used to extract the water trapped in aquifers?

1. Water tank

2. Dam

3. Tube well

4. Canal

Q.

Which of the following is NOT a pollutant?

1. Garbage dumped on streets

2. Oil in a tanker

3. Emission from cars

4. Chemical fertilisers sprayed on plants

Q.

High temperature waste water from industries leads to thermal pollution.

1. True

2. False