CBSE Class 7 - Science - CH 8 - Wastewater Story (MCQs)

Wastewater Story 

Waster Water Treatment Workflow
Leonard G. at English Wikipedia
[CC BY-SA 2.5 (http://creativecommons.org/licenses/by-sa/2.5)],
via Wikimedia Commons

MCQs based on NCERT Chapter

Q1: The light materials which float during waste water treatment is

(a) sludge
(b) scum
(c) sewerage
(d) biogas



Q2: Which of the following is produced during waste water treatment?

(a) sludge
(b) biogas
(c) both biogas and sludge
(d) none of these



Q3: Contaminated water disease is

(a) gastroenteritis
(b) malaria
(c) flu
(d) none of these



Q4: Which of the following is a part of waste water treatment plant?

(a) clarifier
(b) aeration tank
(c) vertical bars
(d) all of these





Q5: Which of the following is a FALSE statement?

(a) Solid wastes such as tea leaves and soft toys should be thrown in dustbin.
(b) Chemicals like paints and medicines should not be thrown in sink.
(c) Cooking oil should be thrown down in the wash basin.
(d) Polythene bags should not be thrown in the drains.



Q6: Activate sludge is about ______ water.

(a) 10%
(b) 25%
(c) 79%
(d) 97%



Q7: Which of the following trees should be grown nearby sewage ponds?

(a) Eucalyptus trees
(b) Ashoka trees
(c) Mango trees
(d) Banana trees



Q8: Which of the following is an example of low cost onsite sewage disposal system?

(a) septic tanks
(b) chemical toilets
(c) composting pits
(d) all of these



Q9: Sewage is a _______ waste which causes which causes water and soil pollution.

(a) solid
(b) liquid
(c) gaseous
(d) all of these



Q10: Which microbe is used to decompose sludge into bio gas?

(a) aerobic bacteria
(b) anaerobic bacteria
(c) algae
(d) fungi



Answers:

1: (b) scum
2: (c) both biogas and sludge
3: (a) gastroenteritis
4: (d) all of these
5: (c) Cooking oil should be thrown down in the wash basin.
6: (d) 97%
7: (a) Eucalyptus trees
8: (d) all of these
9: (b) liquid
10: (b) anaerobic bacteria