Question 1

Question 2(v)Assertion (A): Electrostatic precipitators remove gaseous air pollutants by attracting them to electrically charged plates.Reason (R): The electrostatic precipitators can remove upto 90% of particulate matter from thermal plants.A is True and R is False.A is False and R is True.Both A and R are True.Both A and R are False.

Accepted Answer

A is False and R is True.Reason — Electrostatic precipitators are designed to remove particulate matter (like dust, ash, and soot), not gaseous pollutants.Electrostatic precipitators are highly efficient and can remove up to 90–99% of particulate matter, depending on their design and maintenance. This helps reduce harmful emissions and improve air quality.

Question 2

Question 3Describe the procedure usually used to produce compost.

Accepted Answer

Composting means putting the waste organic matter to decay so that it can be used for fertilizing the agricultural land. The procedure to produce compost is described below:A trench of about 5m long, 1.5m wide and 1.5m deep is dug.A layer of well mixed refuse and waste is spread in it for about 30cm thickness.This layer is fully wetted with a watery mixture of cow-dung and some mud.A second layer of mixed refuse is spread over the first layer till the heap rises to project over the ground level by about half a metre.Leave the set up undisturbed for around 3 months during which water is sprinkled at regular intervals.A trench is then opened and the material is taken out and rearranged in conical heaps and covered with a layer of soil.Compost is ready after 50-60 days to be used in fields for cultivation or in garden flower beds, etc.

Question 3

Question 4Describe the usefulness of incineration of wastes, and also mention the precautions required in it.

Accepted Answer

Incineration is the disposal of waste by burning which causes the release of fumes and other toxic substances.Usefulness of incineration of wastes:The ash left over occupies much less landfill space.Electricity can be generated from the heat released during burning.Precautions:The process should be carried out at very high temperatures.Should be equipped with pollution control devices.Incinerators should be installed away from residential areas.

Question 4

Question 6Name two types of devices used for removing particulate air pollutants.

Accepted Answer

ScrubbersElectrostatic precipitators

Question 5

Question 1Define the terms:(a) Waste(b) Fly ash(c) E-wastes(d) Composting(e) Mine tailing

Accepted Answer

(a) Waste is any substance which is discarded after primary use, or is worthless, defective and of no use.(b) Fly ash is gaseous waste of cement industry which contains fine solid particles of non-combustible ash.(c) e-Wastes are electronic wastes that consist of discarded appliances using electricity like computers, TVs, etc.(d) Composting means putting the waste organic matter to decay so that it can be used for fertilizing the agricultural land.(e) Mine tailing are the left-over material after the processing of the mined products like copper, silver, gold, etc.

Question 6

Question 2Give reasons for the following:(a) Broken glass utensils are a kind of non-degradable waste.(b) Landfills are coming up fast near large cities.(c) Why is municipal sewage first separated into degradable and non-degradable wastes?

Accepted Answer

(a) Broken glass utensils are a kind of non-degradable waste as they cannot be decomposed and broken down by living micro-organisms. These need to be disposed in deeply dug pits so as to cause no harm. One of the applications of broken glass is that it can be used in glass industries in larger quantities after melting.(b) Large cities are seeing huge population growth and they lack in the usage of efficient and safe disposal method for the waste generated in these cities. Large cities are producing large quantities of non-degradable waste that ends up in landfills for disposal. Due to these reasons, landfills are coming up fast near large cities.(c) Municipal sewage is first separated into degradable and non-degradable wastes because degradable wastes can be broken down into non-toxic waste in septic tanks, while non-degradable waste requires to be buried at safe places in order to avoid hazardous effects.

Waste Generation and Management

Assertion Reason Type

Long Answer Type

Progress Check 2

Short Answer Type