Class 7 chemistry MCQs with answers are provided here for Chapter 18, Wastewater Story. These MCQs are based on the CBSE board curriculum and correspond to the most recent Class 7 chemistry syllabus. By practising these Class 7 multiple choice questions, students will be able to quickly review all of the ideas covered in the chapter and prepare for the Class 7 annual examinations as well as other competitive exams.
Download Chapter 18 Wastewater Story MCQs PDF by clicking on the button below.
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Class 7 Wastewater Story MCQs
1. World water day is celebrated every year on _______.
a) 21 March
b) 21 June
c) 22 March
d) None of the above
Answer: c
2. The general assembly of the United Nations proclaimed ______ period as the International decade for action on “Water for life”.
a) 2005 to 2015
b) 2015 to 2025
c) 2004 to 2014
d) None of the above
Answer: a
3. Which organism converts human excreta into vermi-cakes in vermi processing toilets?
a) Bacteria
b) Earthworms
c) Microorganisms
d) None of the above
Answer: b
4. Which of the following settles as a solid in the bottom during wastewater treatment?
a) Sewage
b) Sludge
c) Litter
d) All of the above
Answer: b
Explanation: Sludge is a solid slurry from eclectic industrial processes during wastewater treatment.
5. What do we call the network of big and small pipes carrying wastewater?
a) Sewer
b) Sewage
c) Sewerage
d) None of the above
Answer: c
Explanation: Sewerage is a network of big and small pipes, pumping stations, and appurtenances that transfer sewage from its origin to treatment and disposal.
6. Which of the following are the characteristics of wastewater?
a) Rancid taste
b) Offensive smell
c) Dirty look
d) All of the above
Answer: d
Explanation: Wastewater is typically characterised by a dirty look, grey colour, offensive smell, rancid taste, etc. It has a solid content of about 0.1%.
7. Which of the following is a stage in wastewater treatment?
a) Filtration
b) Aeration
c) Chlorination
d) All of the above
Answer: d
Explanation: Filtration, aeration, and chlorination are the three stages of wastewater treatment. Filtration is the first stage of wastewater treatment. During filtration, the solid particles such as sand, gravel, human washes and floating materials are entirely removed from the water. Aeration is the second stage of wastewater treatment. During aeration, the air is blown on the sedimentation tank’s solid impurities that settle (sludge). And the last stage of wastewater treatment is chlorination. During chlorination, chlorine is added to the wastewater to kill the microorganisms present in the wastewater.
8. Which of the following is a source of wastewater?
a) Industry
b) Household
c) Hospital
d) All of the above
Answer: d
9. What are the byproducts of wastewater treatment?
a) Sludge and biogas
b) Sludge and scum
c) Sludge and fleece
d) All of the above
Answer: a
10. What is the full form of WWTP?
a) Wastewater treatment plant
b) Wreckagewater treatment plant
c) Both (a) and (b)
d) None of the above
Answer: a
11. Which of the following is used to disinfect wastewater?
a) Ozone
b) Chlorine
c) UV light
d) All of the above
Answer: d
Explanation: Ozone, chlorine and UV light are used to decrease the number of microorganisms in the wastewater.
12. The liquid waste with dissolved and suspended impurities is known as ______.
a) Portable water
b) Wastewater
c) Groundwater
d) None of the above
Answer: b
13. Which of the following blocks the drain?
a) Fat
b) Oil
c) Both (a) and (b)
d) None of the above
Answer: c
14. Disinfection is which step in the wastewater treatment plant?
a) First
b) Second
c) Last
d) None of the above
Answer: c
Explanation: Disinfection is the last step in the wastewater treatment plant. It can be performed by using ozone, chlorine or UV light. During disinfection, disinfectant is added to the wastewater to kill the microorganisms present in the wastewater.
15. Which of the following can be decomposed in an aerated tank?
a) Organic matter
b) Inorganic matter
c) Both (a) and (b)
d) None of the above
Answer: a
16. Suspended impurities contained in sewage are known as ______.
a) Sludge
b) Contaminants
c) Fleece
d) None of the above
Answer: b
17. Which of the following equipment is used to remove floatable particles from wastewater?
a) Bar screen
b) Sedimentation tank
c) Both (a) and (b)
d) None of the above
Answer: a
18. Which of the following is a water-borne disease?
a) Typhoid
b) Tuber
c) Both (a) and (b)
d) None of the above
Answer: a
19. Which of the following is an inorganic impurity of sewage?
a) Garbage
b) Vegetable waste
c) Excreta
d) None of the above
Answer: d
20. Sewage is a ______ waste.
a) Solid
b) Liquid
c) Gaseous
d) All of the above
Answer: b
Read Also:
- Sewage – Wastewater and Its Management
- Sewage Management Methods
- Water Questions
- Importance of Water (H2O)
- Water Scarcity
- Uses of Water
- Chemistry Worksheet Class 7 on Chapter 18 Wastewater Story with Answers – Set 1
- Chemistry Worksheet Class 7 on Chapter 18 Wastewater Story with Answers – Set 2
- Chemistry Worksheet Class 7 on Chapter 18 Wastewater Story with Answers – Set 3
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