Class 7 Waste Water Story CBSE Questions & Answers

Class 7 · Waste Water Story

This is Science Class 7 Waste water Story CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
In water works, first step is
  • A
    Aeration
  • B
    Sedimentation
    Correct
  • C
    Chlorination
  • D
    Filtration
2
Biodegradable waste
  • A
    Enters the food chains then causes bio magnification
  • B
    Does not decompose
  • C
    Decomposes in nature by microbes (
    Correct
  • D
    Accumulates in environment
3
River Yamuna is polluted near Delhi due to
  • A
    Thermal plant on its bank
  • B
    Addition of untreated sewage
    Correct
  • C
    Water animals
  • D
    Rivers joining it
4
Contaminants are
  • A
    Chemical impurities only
  • B
    Physical impurities
  • C
    Biological impurities only
  • D
    Dissolved and suspended impurities
    Correct
5
Trade wastes is released from
  • A
    Toilets
  • B
    Industrial and commercial organization
    Correct
  • C
    Kitchens
  • D
    Bathrooms
6
Sewer system is useful in
  • A
    Winter season only
  • B
    Summer season only
  • C
    All seasons
    Correct
  • D
    Rainy season only
7
Solid organic wastes in sewage water can be used to
  • A
    Recycle paper
  • B
    Manufacture fertilizers
  • C
    All of these
  • D
    Produce biogas
    Correct
8
Large objects like plastic bottles, plastics and cans are removed by
  • A
    Chlorination
  • B
    Sedimentation
  • C
    Bar screen
    Correct
  • D
    Aeration
9
which of the following is wastewater?
  • A
    water trickling from a damaged tap
  • B
    water coming out of a shower
  • C
    water coming out of laundry
    Correct
  • D
    water flowing in ariver
10
Which method is used to make sea water fit for drinking?
  • A
    Filtration
  • B
    Reverse osmosis
    Correct
  • C
    Sedimentation
  • D
    Alternate osmosis
11
Biogas plant can be used to generate energy using
  • A
    Fats and grease in sewage
  • B
    Human excreta
    Correct
  • C
    Aerobic bacteria
  • D
    Wet wood
12
Sewage water is slightly acidic due to
  • A
    High pH
  • B
    Low pH
    Correct
  • C
    Neutral pH
  • D
    High acidic nutrient
13
Stone and girt present in sewage forms the
  • A
    Lodging
  • B
    Sludge
    Correct
  • C
    Lithotrips
  • D
    Sever
14
We should not use ponds water for drinking without treating it because ponds water may be
  • A
    Devoid of minerals
  • B
    Poisonous
  • C
    High salt containing
  • D
    Contaminated
    Correct
15
Algal bloom is caused due to addition of
  • A
    Inorganic matters in water bodies
  • B
    Organic matters in water bodies
    Correct
  • C
    Any one of the following
  • D
    Chemical substance in water bodies