NIOS Class 12 Environmental Science Chapter 35 Renewable Sources of Energy – II

NIOS Class 12 Environmental Science Chapter 35 Renewable Sources of Energy – II Solutions to each chapter is provided in the list so that you can easily browse throughout different chapters NIOS Class 12 Environmental Science Chapter 35 Renewable Sources of Energy – II Notes and select need one. NIOS Class 12 Environmental Science Chapter 35 Renewable Sources of Energy – II Question Answers Download PDF. NIOS Study Material of Class 12 Environmental Science Paper Code 333.

NIOS Class 12 Environmental Science Chapter 35 Renewable Sources of Energy – II

Also, you can read the NIOS book online in these sections Solutions by Expert Teachers as per National Institute of Open Schooling (NIOS) Book guidelines. These solutions are part of NIOS All Subject Solutions. Here we have given NIOS Class 12 Environmental Science Chapter 35 Renewable Sources of Energy – II Solutions, NIOS Senior Secondary Course Environmental Science Solutions for All Chapter, You can practice these here.

Renewable Sources of Energy – II

Chapter: 35

Module 8 B: Energy and Environment

Textual Question Answer

INTEXT QUESTIONS 30.1

1. Define biomass and list various sources of biomass.

Ans: Biomass is an accumulation of organic matter such as plant and animal materials (living or dead). It is a renewable energy source. Eg. agricultural wastes and residues. 

2. What is biomass conversion?

Ans: Biomass conversion is the process of obtaining energy or fuel from the chemical energy stored in biomass. 

3. Why is biomass considered as an indirect form of solar energy?

Ans: Biomass consists of green plants which convert solar energy to chemical energy by photosynthesis, animals which feed upon plants and store chemical energy. Biomass can be burned directly as solid fuel or converted into alcohol or into biogas. So the fuel energy of biomass is actually locked up solar energy. 

4. Give two advantages of using biomass fuel.

Ans: Uses of biomass energy:

(i) It does not add CO₂ to the atmosphere.

(ii) It can be used to generate electricity easily. 

(iii) It constitutes a major form of renewable resource of energy. 

5. What are petro crops? List any two such plants.

Ans: Plants that produce hydrocarbons in substantial amount and can act as alternative energy source are called petrocrops. Examples Jatropha curcas, Calotropis procure (or any other). 

INTEXT QUESTIONS 30.2 

1. Define geothermal energy and list its uses. Give some examples from where this form of energy can be trapped.

Ans: Geothermal energy is the natural heat from the interior of the earth which can be used for heating buildings and generating electricity.

Examples of sites where geothermal energy can be tapped are volcanoes, hot springs, and geysers.

2. Describe the disadvantage and advantage of use of geothermal energy.

Ans: Advantages of geothermal energy:

(i) Most energy efficient.

(ii) Cost effective and environmentally clean.

Disadvantages:

(i) Steam contains H₂O which has the odour of rotten eggs. 

(ii) The minerals in the steam are also toxic to fishes and also corrosive to the pipes and equipment. 

3. “Hydrogen energy is called fuel for next generation”, Comment on the statement.

Ans: Hydrogen is available in plenty and when it burns in presence of oxygen it produces non-polluting water vapour. It is a clean source of energy. Technology is needed to get free hydrogen as fuel and cost effective fuel cells need to be developed.

4. Where in India is the most promising geothermal field located.

Ans: Puga valley in the Ladakh region.

TERMINAL EXERCISE

1. List the renewable sources of energy which are ideal for the coming times. 

Ans: The renewable energy forms suitable for the future are:

(i) Biomass energy.

(ii) Geothermal energy.

(iii) Hydrogen energy.

2. Describe the advantages of hydrogen as a fuel. Do you think hydrogen will become a major source of energy? Give reasons for your answer. 

Ans: Advantages of using hydrogen as a fuel are:

(a) Less pollution as water is the by-product.

(b) No CO₂ emission so controls the danger of global warming.

(c) Renewable energy resources such as hydrogen are the most abundant element in the universe.

Hydrogen will become a major source of energy in the future. It is a clean source of energy. When hydrogen combines with oxygen to release a large amount of energy. water is the by-product formed. There is no CO₂ emission. Hence there are no problems with the greenhouse effect and global warming. Being the most abundant element in-universe, hydrogen is a renewable resource. Only the initial expense for setting up the cells to produce energy from hydrogen will be higher. But considering the fuel efficiency, hydrogen as a fuel is cost-effective.

3. Describe fuel cell technology and its advantages. 

Ans: Fuel cells are highly efficient power-generating systems that produce electricity by combining hydrogen and oxygen in an electrochemical reaction. A fuel cell consists of an electrolyte sandwiched between two electrodes. Oxygen passes over one electrode and hydrogen over the other, and they react electrochemically to generate electricity, water, and heat. The flow of electrons from the negative to the positive electrode supplies current to run devices.

The only by-product is water, which makes fuel cells pollution-free and a clean energy source.

Advantages:

(i) High efficiency compared to conventional systems.

(ii) Non-polluting, as the only by-product is water.

(iii) Quiet operation and low maintenance.

(iv) Can be used in vehicles, spacecraft, and stationary power plants.

4. Why are fuel cells more efficient in generating electricity in comparison to traditional systems? 

Ans: Fuel cells convert chemical energy directly into electrical energy. The by-product formed is water and there is no emission of polluting gases like CO₂. And so, it is highly efficient. In traditional systems combustion of fuels indirectly generates electricity. Combustion produces heat energy in the form of steam. This is used to rotate the turbine to generate electricity. This involves loss of heat and thus is not very efficient.

5. Draw a schematic representation of a biogas plant and label its parts. 

Ans: 

6. What are the limitations of (i) fuel cells (ii) geothermal energy? (any two) 

Ans: (i) Limitations of fuel cells –

(a) High installation cost.

(b) High maintenance cost.

(ii) Limitations of geothermal energy –

(a) Noise pollution at drilling sites.

(b) Air pollution due to emission of gases.

7. How is the fuel obtained from petrocrops? 

Ans: Biocrude can be used as fuel. Fuel can be obtained from petrocrops by tapping the latex, followed by coagulation. When latex tapping is impossible fuel can be obtained by extractíon of the dry biomass using a suitable solvent. Hydrocracking of bio-crude can convert it into several useful products like gasoline (automobile fuel), gas oil, and kerosene.

8. Discuss advantages and disadvantages of geothermal energy.

Ans: Advantages of geothermal energy are:

(i) Cheap.

(ii) Versatile use

(iii) High energy content.

(iv) Less pollution.

(v) Renewable resource.

(vi) Minerals are obtained.

(vii) Multiple-use from a single resource.

Disadvantages of geothermal energy are:

(i) Less efficient.

(ii) Extraction results in surface subsidence or settlement.

(iii) Corrosive gases like hydrogen sulfide, CO₂, ammonia, etc are formed.

(iv) Drilling causes noise pollution. 

(v) Discovery of the resource is difficult.

(vi) Installation of equipment is also difficult.