Wastewater Story Class 7 MCQ Science Chapter 13

Class 7 Science Chapter 13 MCQ Wastewater Story

MCQ on Wastewater Story Class 7

Select and write the most appropriate option out of the four options given

I. Multiple Choice Questions

Question 1.
On March 22 2005, the General Assembly of the United Nations proclaimed the period …………
A) 2010-2015
B) 2005-2015
C) 2014-2020
D) 2015-2020
Answer:
B) 2005-2015

Wastewater Story Class 7 MCQ Science Chapter 13

Question 2.
Select the correct statement(s).
i) Cleaning of water is a process of removing pollutants before it enters a water body or is reused.
ii) The process of wastewater treatment is known as ‘Sewage Treatment’.
iii) Wastewater is the dirty, black-brown water that flows down the drains from sinks, showers, toilets, etc. from our homes.
iv) Every human being has equal access to safe drinking water on earth.
A) (i) and (ii)
B) (i), (ii) and (iii)
C) Only (iv)
D) (iii) and (iv)
Answer:
B) (i), (ii) and (iii)

Question 3.
Increasing scarcity of freshwater is due to
i) population growth
ii) pollution
iii) industrial development
iv) mismanagement.
A) (i) and (ii)
B) (i),(ii) and (iii)
C) (ii) and (iii)
D) All of these
Answer:
D) All of these

Wastewater Story Class 7 MCQ Science Chapter 13

Question 4.
An inorganic impurity present in sewage is
A) oil
B) urea
C) nitrate
D) bacteria
Answer:
D) bacteria

Question 5.
Contamination of drinking water with sewage water can cause diseases like………….. in people consuming it.
A) dysentery
B) typhoid
C) cholera
D) all of these
Answer:
D) all of these

Question 6.
Organic impurities present in sewage are
A) bacteria
B) metals
C) pesticides
D) nutrients.
Answer:
C) pesticides

Question 7.
Which chemical is added to the wastewater to treat it ?
A) Sulphur
B) Chlorine
C) Nitrate
D) Pesticide
Answer:
B) Chlorine

Wastewater Story Class 7 MCQ Science Chapter 13

Question 8.
Select the correct sequence of steps involved to treat polluted water.
A) Sewage → Aeration → Filtration → Chlorination
B) Sewage → Filtration → Aeration → Chlorination
C) Sewage → Chlorination → Filtration → Aeration
D) Sewage → Aeration → Chlorination → Filtration
Answer:
A) Sewage → Aeration → Filtration → Chlorination

Question 9.
Select the incorrect statement (s).
i) Manholes are located only at the junction of two or more sewers.
ii) During the process of filtration, filter papers are used to filter solid impurities in wastewater in a treatment plant.
iii) During the treatment of polluted water, we get clear water after adding chlorine tablets into the wastewater.
A) (i) and (iii)
B) (i) and (ii)
C) Only (ii)
D) (ii) and (iii)
Answer:
B) (i) and (ii)

Question 10.
Given image represents a part of the Wastewater Treatment Plant.
Wastewater Story Class 7 MCQ Science Chapter 13.1
Which of the following does not take place here?
i) Solids like faeces are removed with the help of a scraper.
ii) Large objects like rags, sticks, napkins are removed.
iii) Floatable solids like oil and grease are removed.
iv) Air is pumped for growing aerobic bacteria.
A) (i), (iii) and (iv)
B) Only (ii)
C) (i) and (ii)
D) (ii) and (iii)
Answer:
A) (i), (iii) and (iv)

Wastewater Story Class 7 MCQ Science Chapter 13

Question 11.
Why clarified water is aerated in a Wastewater Treatment Plant?
A) To help anaerobic bacteria to grow.
B) To help aerobic bacteria to grow.
C) To remove the suspended particles floating on the surface of clarified water.
D) To mix the anaerobic bacteria well with the clarified water.
Answer:
B) To help aerobic bacteria to grow.

Question 12.
Select the incorrect statements
In a grit and sand removal tank,
i) the speed of the incoming wastewater is decreased.
ii) sludge is removed from the wastewater.
iii) biogas is produced.
iv) sand, grit and pebbles present in the sewage are settled down.
A) (i), (ii) and (iii)
B) (ii) and (iii)
C) (i) and (ii)
D) (i),(iii) and (iv)
Answer:
B) (ii) and (iii)

Question 13.
Which of the following is not a water-borne disease?
A) Cholera
B) Malaria
C) Typhoid
D) Hepatitis
Answer:
B) Malaria

Question 14.
Untreated human excreta is a health hazard. It results in
A) pollution of soil and water
B) spread of water-borne diseases
C) contamination of ground water and surface water
D) all of these
Answer:
D) all of these

Question 15.
Seems was suffering from dysentery. What could be the cause?
A) She drank contaminated water.
B) She did not eat a balanced diet.
C) She drank filtered water.
D) She got bitten by mosquito causing dysentery.
Answer:
A) She drank contaminated water.

Wastewater Story Class 7 MCQ Science Chapter 13

Question 16.
Which of the following is not a low cost onsite sewage disposal system ?
A) Vermi-processing toilet
B) Composting pits
C) Septic tanks
D) None of these
Answer:
D) None of these

Question 17.
What is true about a vermi-processing toilet ?
A) It is a novel, low water-use toilet.
B) Human excreta is treated by earthworms.
C) Human excreta is completely converted to vermicastings.
D) All of these
Answer:
D) All of these

Question 18.
Which of the following methods should not be adopted if no sewage system is available?
A) Allowing untreated sewage to flow into the rivers.
B) Making septic tanks for sewage disposal.
C) Allowing sewage to flow into a biogas plant.
D) Using a vermi composting toilet.
Answer:
A) Allowing untreated sewage to flow into the rivers.

Question 19.
Which of the following options includes organic impurities present in the sewage?
A) Nitrates, phosphates and nitrogen
B) Disease causing bacteria and microbes
C) Phosphorus and metals
D) Urea, pesticides, herbicides, etc.
Answer:
D) Urea, pesticides, herbicides, etc.

Wastewater Story Class 7 MCQ Science Chapter 13

Question 20.
Select the incorrect statements.
i) Wastewater can never be reused.
ii) Sewage is a liquid waste.
iii) Wastewater is generated only in public places.
iv) Rainwater is not a part of wastewater.
A) (i) and (iii)
B) (ii) and (iv)
C) (ii) and (iii)
D) (i), (iii) and (iv)
Answer:
D) (i), (iii) and (iv)

Question 21.
Aeration is done during the wastewater treatment to
i) remove foul smell from the sewage.
ii) enhance the growth of anaerobic bacteria.
iii) enhance the growth of aerobic bacteria.
A) (i) and (iii)
B) (i) and (ii)
C) Only (i)
D) only (ii)
Answer:
A) (i) and (iii)

Question 22.
Given figure represents a part of the Wastewater Treatment Plant. Which of the following steps takes place here ?
Wastewater Story Class 7 MCQ Science Chapter 13.2
A) Solids like faeces are removed with a scraper.
B) Water is treated with chlorine.
C) Solids like large pieces of plastics, cans, etc. are removed.
D) Sand, grit and pebbles are removed from wastewater.
Answer:
A) Solids like faeces are removed with a scraper.

Wastewater Story Class 7 MCQ Science Chapter 13

Question 23.
Select the incorrect statement(s).
i) Vermi-cakes are a rich source of nutrients needed for soil.
ii) Activated sludge contains human excreta.
iii) Sludge obtained in the sedimentation tank is rich in soil nutrients.
iv) Biogas is used as a fuel.
A) (i) and (ii)
B) (ii) and (iii)
C) Only (ii)
D) (i), (iii) and (iv)
Answer:
B) (ii) and (iii)

Question 24.
Select the incorrect statement(s) about biogas.
i) It is used as manure and fertiliser
ii) It is a methane rich gas.
iii) It is also called as gobar gas.
iv) It is one of the major cause of pollution.
A) (i) and (ii)
B) (i) and (iv)
C) (ii) and (iii)
D) Only (iv)
Answer:
D) Only (iv)

II. Fill in the blanks

1. In a treatment plant, wastewater is first passed through ………… to remove large objects.
Answer: bar screens

2. Solids like faeces which settle at the bottom of the sedimentation tank is called ………..
Answer: sludge

3. Wastewater which is free from large objects, sludge and floatable solids like oil and grease, is called …………
Answer: clarified water

4. A ………… is used to remove floatable oil and grease from wastewater.
Answer: skimmer

5. Sludge is decomposed with the help of ………… bacteria to produce ………..
Answer: anaerobic, biogas

6. In the aeration tank, the growing ………… bacteria can consume human waste, food waste, soaps and other unwanted matter in the clarified water.
Answer: aerobic

Wastewater Story Class 7 MCQ Science Chapter 13

7. The water from the activated sludge is removed by ………… or machines.
Answer: sand drying beds

8. ………… is used as manure, organic matter and nutrients to the soil.
Answer: dried sludge

9. Disinfectants such as ………… and ………… are added to the treated water before releasing it into the distribution system.
Answer:  chorine, ozone

10. The low quantity of organic material and suspended matter still remaining in the treated water is cleaned up by ………… when discharged into the water bodies.
Answer: nature

III. True Or False

1. We must clean wastewater by removing pollutants in it and then reuse it.
Answer: True

2. Everyone on the earth has equal access to clean and safe drinking water.
Answer: False

Wastewater Story Class 7 MCQ Science Chapter 13

3. The main aim of the action of ‘Water for life’ is to reduce by half the number of people who do not have access to safe drinking water.
Answer: True

4. Sludge and floatable solids are removed from wastewater with the help of a scraper.
Answer: False

5. The water coming from the sedimentation tank is very clear and free from suspended solids.
Answer: True

6. Solids like faeces, food waste, etc., which get settled down in the aeration tank is called activated sludge.
Answer: True

7. Biogas is used only as a fuel.
Answer: False

Wastewater Story Class 7 MCQ Science Chapter 13

8. Waste generation is a natural part of human activity.
Answer: True

9. We can limit the type of waste and quantity of waste produced.
Answer: True

10. Dried sludge is used as a fuel and to produce electricity.
Answer: False

11. Domestic waste does not contain microorganisms.
Answer: False

12. Aeration tanks contain anaerobic bacteria.
Answer: False

13. Oils and fats can clog the soil pores and reduce water șeepage through it.
Answer: True

14. Dried sludge is an expensive manure used for adding nutrients to the soil.
Answer: False

15. Gobar gas is used only as a fuel while biogas cande used as a fuel as well as to generate electricity.
Answer: False

Wastewater Story Class 7 MCQ Science Chapter 13

16. Faeces that settle down in the sedimentation tank can be removed by using a scraper.
Answer: True

17. Cholera, typhoid and jaundice are water-borne diseases.
Answer: True

18. In verm i-composting toilets, microorganisms are used to break down
Answer: False

IV. Matching

Question 1.

Column-I Column-II
a) Bar screens i) Sludge is removed
b) Clarifiers ii) Removes foul smell from sewage
c) Aerators iii) First step in WWTP
d) Digesters iv) Contains anaerobic bacteria

A) a – (i), b – (ii), c – (iv), d – (iii)
B) a – (iii), b – (i), c – (ii), d – (iv)
C) a – (iii), b – (i), c – (iv), d – (ii)
D) a – (ii), b – (iii), c – (i), d – (iv)
Answer:

Column-I Column-II
a) Bar screens iii) First step in WWTP
b) Clarifiers i) Sludge is removed
c) Aerators ii) Removes foul smell from sewage
d) Digesters iv) Contains anaerobic bacteria

Wastewater Story Class 7 MCQ Science Chapter 13

Question 2.

Column – I Column – II
a) Filtration i) Heavy matter settles at the bottom to form sludge
b) Disinfection ii) Addition of chlorine in water to kill pathogens
c) Sedimentation iii) Water percolates through layers of sand and gravel
d) Aeration iv) Exposure of wastewater to circulating air

A) a – (iii), b -(ii), c – (i), d – (iv)
B) a – (iii), b – (i), c – (iv), d – (ii)
C) a – (ii), b – (iii), c – (i), d – (iv)
D) a – (i), b – (iv), c – (ii), d – (iii)
Answer:

Column – I Column – II
a) Filtration iii) Water percolates through layers of sand and gravel
b) Disinfection ii) Addition of chlorine in water to kill pathogens
c) Sedimentation i) Heavy matter settles at the bottom to form sludge
d) Aeration iv) Exposure of wastewater to circulating air

 

Class 7 Science MCQ

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