CBSE Class 10 Science Sustainable Management of Natural Resources Assignment Set D

Question. From the list given below pick the item that is not a natural resource-
(a) Soil
(b) Water
(c) Electricity
(d) Air

Answer: C

Question. The most rapidly dwindling natural resource in the world is-
(a) water
(b) forests
(c) wind
(d) sunlight

Answer: B

Question. Which one of the following gases is the major constituent of biogas?
(a) CO₂
(b) H₂
(c) CH₄
(d) O₂

Answer: C

Question. Which one of the following is a renewable resource?
(a) Natural gas
(b) petroleum
(c) ground water
(d) coal

Answer: A

Question. The pH range most conducive for life of fresh water plants and animals is
(a) 6.5 – 7.5
(b) 2.0 – 3.5
(c) 3.5 – 5.0
(d) 9.0 – 10.5

Answer: A

Assertion and Reason Type Questions

For questions given below, two statements are given-one labeled Assertion(A) and the other labeled Reason(R). Select the correct answer to these questions from the codes (i),(ii),(iii) and(iv) as given below:
(i) Both assertion (A) and Reason (R) are true and reason is correct explanation of assertion.
(ii) Both assertion (A) and Reason (R) are true but reason is not the correct explanation of the assertion.
(iii) Assertion (A) is true but reason (R) is false
(iv) Assertion (A) is false but reason (R) is true.

Question. Assertion: Presence of coliform bacteria indicates pollution by sewage.
Reason: Industrial effluents are free from coliform bacteria.
Answer: (ii)

Question. Assertion: Pollution of water is indicated by alkaline pH.
Reason: Alkaline pH indicates hardness.
Answer: (iv)

Question. Assertion: Broken glass is picked up by rag pickers for recycling.
Reason: Recycling reduces the piling of waste.
Answer: (i)

Question. Assertion: Wildlife is the living component of forests.
Reason: Forests protect the soil from erosion.
Answer: (ii)

Question. Assertion: More trees should be grown in water shed areas.
Reason: They retain water and protect the soil from erosion.
Answer: (i)

Short Answer Type Questions

Question. What would be the advantages of exploiting resources with short-term areas?
Answer: Exploitation of resources with short-term aims means misuse of the resource and harm to the earth.

Question. What changes can you make in your habits to become more environment friendly?
Answer: (i) Do not throw garbage on the road side.
(ii) Switch off lights, fans, TV when not required.
(iii) Use less water for bathing, washing jobs.
(iv) Use jute bags instead of polyethene.
(v) Walk or cycle to cover short distances.

Question. What can you as an individual do to reduce your consumption of the various natural resources?
Answer: By following 3 R’s
(a) Reduce: Reduce or minimise the use of resources, by saving electricity by switching off unnecessary lights. and fans etc. and by walking, whenever possible.
(b) Recycle: Collect and recycle the products like plastic, paper, glass and metal.
(c) Reuse: It is better than recycle. Instead of throwing used envelopes. We can reverse it

Question. Find out about the traditional systems of water harvesting/management in your region.
Answer: The traditional systems of water harvesting management:
• Bandharas and talc in Maharashtra
• Bundhis in Madhya Pradesh and Uttar Pradesh
• Kulhs in Himachal Pradesh
• Khadins, tanks and nadir in Rajasthan.
• Ahars and pynes in Bihar.

CCT Based Questions

1. TOPIC – LPG IS BETTER FUEL THAN WOOD (COAL & PETROLEUM)

Ishita a student of class 8 went to meet her classmate Divya. They discussed on subject related matter. Ishita met her mother also in kitchen before leaving. She observed that her Mother is boiling water in an open container. She also observed that the colour of flame is yellow. Ishita suggested her Friend’s mother to put lid over container while boiling water/milk for saving of fuel. She also suggested getting periodic servicing of LPG gas stove from authentic technician to increase the efficiency

QUESTIONS-

Question. What does yellow flame indicate?
(a) High caloric value of fuel
(b) Low caloric value of fuel
(c) Low temperature
(d) None of these

Answer: B

Question. What is the full form of LPG.
(a) Liquid petroleum gas
(b) Liquified petroleum gas
(c) Low petroleum gas
(d) None of these

Answer: A

Question. What does calorific value of a fuel mean?
Answer: It is the quantity of heat produced by the burning of fuel.

Question. Why is the saving of fuel necessary?
Answer: To conserve fuel and save environment from pollution.

Question. Name the constituents of petroleum.
Answer: 1 Petrol
2. Kerosene
3. Diesel
4. Paraffin wax,
5. lubricating oil
6. Bitumen

Question. What is the composition of LPG?
Answer: Propane, butane and various mixture of other gases.

2.TOPIC-OZONE

Read the following section of an article about the ozone layer.
The atmosphere is an ocean of air and a precious natural resource for sustaining life on the Earth. Unfortunately, human activities based on national/personal interests are causing harm to this common resource, notably by depleting the fragile ozone layer, which acts as a protective shield for life on the Earth. Ozone molecules consist of three oxygen atoms, as opposed to oxygen molecules which consist of two oxygen atoms. Ozone molecules are exceedingly rare: fewer than ten in every million molecules of air. However, for nearly a billion years, their presence in the atmosphere has played a vital role in safeguarding life on Earth. Depending on where it is located, ozone can either protect or harm life on Earth. The ozone in the troposphere (up to 10 kilometers above the Earth’s surface) is “bad” ozone which can damage lung tissues and plants. But about 90 percent of ozone found in the stratosphere (between 10 and 40 kilometers above the Earth’s surface) is “good” ozone which plays a beneficial role by absorbing dangerous ultraviolet (UV-B) radiation from the Sun.
Without this beneficial ozone layer, humans would be more susceptible to certain diseases due to the increased incidence of ultra-violet rays from the Sun. In the last decades the amount of ozone has decreased. In 1974 it was hypothesized that chlorofluorocarbons (CFCs) could be a cause for this. Until 1987, scientific assessment of the cause-effect relationship was not convincing enough to implicate CFCs. However, in September 1987, diplomats from around the world met in Montreal (Canada) and agreed to set sharp limits to the use of CFCs.

Question. Ozone is also formed during thunderstorms. It causes the typical smell after such a storm. the author of the text distinguishes between “bad ozone” and “good ozone”.
In terms of the article, is the ozone that is formed during thunderstorms “bad ozone” or “good ozone”?
Choose the answer and the explanation that is supported by the text

Answer: Full credit: B. Bad. It is formed in the troposphere.

Question. “Without this beneficial ozone layer, humans would be more susceptible to certain diseases due to the increased incidence of ultra-violet rays from the Sun.”
Name one of these specific diseases.

Answer: Full credit: Answers which refer to skin cancer.

3.TOPIC- ACID RAIN

Below is a photo of statues called Caryatids that were built on the Acropolis in Athens more than 2500 years ago. The statues are made of a type of rock called marble. Marble is composed of calcium carbonate.
In 1980, the original statues were transferred inside the museum of the Acropolis and were replaced by replicas. The original statues were being eaten away by acid rain.

Question.Normal rain is slightly acidic because it has absorbed some carbon dioxide from the air.
Acid rain is more acidic than normal rain because it has absorbed gases like sulphur oxides and nitrogen oxides as well.
Where do these sulphur oxides and nitrogen oxides in the air come from?
Answer: Responses that mention any one of: car exhausts, factory emissions, burning fossil fuels such as oil and coal, gases from volcanoes or other similar things.
Burning coal and gas. Oxides in the air come from pollution from factories and industries.
Volcanoes. Fumes from power plants.
They come from the burning of materials that contain sulfur and nitrogen.
– Responses that include an incorrect as well as a correct source of the pollution.
Fossil fuel and nuclear power plants. [Nuclear power plants are not a source of acid rain.]
The oxides come from the ozone, atmosphere and meteors coming toward Earth.
Also, the burning of fossil fuels.
– Responses that refer to “pollution” but do not give a source of pollution that is a significant cause of acid rain.
Pollution.
The environment in general, the atmosphere we live in – e.g., pollution.
Gasification, pollution, fires, cigarettes.
Pollution such as from nuclear power plants.

Question. The effect of acid rain on marble can be modelled by placing chips of marble in vinegar overnight. Vinegar and acid rain have about the same acidity level. When a marble chip is placed in vinegar, bubbles of gas form. The mass of the dry marble chip can be found before and after the experiment.
A marble chip has a mass of 2.0 grams before being immersed in vinegar overnight. The chip is removed and dried the next day. What will the mass of the dried marble chip be?
A. Less than 2.0 grams
B. Exactly 2.0 grams
C. Between 2.0 and 2.4 grams
D. More than 2.4 grams
Answer: Full credit: A. Less than 2.0 grams