Exp) Nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts (lighter nuclei). The fission process often produces free neutrons and photons (in the form of gamma rays) and releases a large amount of energy. In nuclear physics, nuclear fission is either a nuclear reaction or a radioactive decay process. Example: Atom Bomb, Nuclear Energy Development Programme of India.

Solar energy (Sunlight), the Hydrogen bomb, International Thermonuclear Experimental Reactor (Artificial Sun Experiment) are based on Nuclear Fusion.

Source)

Chapter 4; page number 90

Exp) Statement 1 is correct. Flyash is commonly used as a replacement for portable cement. It holds the concrete together by acting as a pozzolan with the lime in cement.

Statement 2 is incorrect. Flyash has also great potential in agriculture because it increases soil health and crop productivity due to a higher concentration of various minerals ( sodium, potassium, zinc, magnesium, iron and calcium). Fly ash or flue ash, also known as pulverised fuel ash in the United Kingdom, is a coal combustion product that is composed of the particulates that are driven out of coal-fired boilers together with the flue gases. Ash that falls to the bottom of the boiler's combustion chamber is called bottom ash.

Source)

Science & Technology by Ravi Agrahari, Chapter 3; page-45

Exp) Statement 1 is incorrect. Nuclear Fission does not occur normally in nature and needs to be induced. Nuclear fusion occurs naturally and is a source of stars, like the sun.

Statement 2 is incorrect. In nuclear fission, many highly radioactive particles are produced while in nuclear fusion, few radioactive particles are produced; however, through fission 'trigger' radioactive particles will result from that.

Source)

Chapter 4; page number 90

Exp) In an ordinary (non-combined cycle) heat engine the remaining heat (i.e., hot exhaust gas) from combustion is wasted. There is a scope for coal-fired power stations to replace their approach with clean coal technology such as Pulvenised coal combustion, Cyclone fired wet bottom boilers and Stroker boilers.

Source)

Science & Technology by Ravi Agrahari; Chapter-3; page-45

Exp) All the pairs are correctly matched.  Methane is processed for fuel and feedstock for urea plants. Propane as well as butane used for the production of LPG.

Ethane is used in the production of ethylene for making plastics, anti-freeze and detergents; it's a ripening agent for foods, a refrigerant, a substance in producing welding gas and a primary ingredient in mustard gas. Ethane is a component in the natural gas methane and is removed by cryogenic liquefaction.

Source)

Science & Technology by Ravi Agrahari; Chapter 3; page 48

Exp) Statement 1 is correct. Methane is extracted from coalfield and contains high calorific value.

Statement 2 is correct. It contains 95 percent of pure methane along with very little propane or butane and natural gas condensate.

Statement 3 is incorrect. It does not contain harmful gases like hydrogen sulphide (H2S). The term refers to methane adsorbed into the solid matrix of the coal. It is called 'sweet gas' because of its lack of hydrogen sulfide. The presence of this gas is well known from its occurrence in underground coal mining, where it presents a serious safety risk.

Coalbed methane is distinct from a typical sandstone or other conventional gas reservoir, as the methane is stored within the coal by a process called adsorption. The methane is in a near-liquid state, lining the inside of pores within the coal (called the matrix). The open fractures in the coal (called the cleats) can also contain free gas or can be saturated with water. Unlike much natural gas from conventional reservoirs, coal bed methane contains very little heavier hydrocarbons such as propane or butane, and no natural-gas condensate. It often contains up to a few percent carbon dioxide.

Source)

Science & Technology by Ravi Agrahari, Chapter 3; page 49

Exp) Gas hydrates (Clathrates) are naturally occurring ice-like combination of natural gas and water found in polar regions. These are solids, made up of hydrocarbon gas (mainly methane) and liquid water. They resemble wet snow and can exist at temperatures above the freezing point of water.Hydrates belong to a form of complexes known as Clathrates. Clathrates are substances having a lattice-like structure, in which molecules of one substance are completely enclosed within crystal structure of another.

Source)

Science & Technology by Ravi Agrahari;  page-A.II.49.

• Option A is the Correct Answer: UDAY Scheme was launched by Union Power Ministry for financial turnaround and revival package for state electricity distribution companies (DISCOMs). It aimed to help to make discoms financially and operationally healthy so they can supply adequate power at affordable rates.

• Option C is the correct Answer: Nuclear Winter, as the theory describes the climatic effects of nuclear war. The smoke from the fires started by nuclear weapons, mainly the sooty, black smoke from cities and industrial areas, would get heated by the sun, lofted into the upper stratosphere and thus spread globally, making it last for years. This results in a cool, dark, dry condition at the Earth’s atmosphere because it does not allow the sunlight to enter into the atmosphere, which would prevent plant growth at least for one growing season, resulting in mass starvation in the world.

Explanation:

• Option B is the Correct Answer: The Government of India set up the Bureau of Energy Efficiency (BEE). on 1st March 2002 under the provisions of the Energy Conservation Act, 2001. The mission of the Bureau of Energy Efficiency is to assist in developing policies and strategies with a thrust on self-regulation and market principles, within the overall framework of the Energy Conservation Act, 2001 with the primary objective of reducing the energy intensity of the Indian economy.

Explanation:

• Statement 1 and 3 is Correct:
• It is a policy adopted by the Government of India indicating the new contractual and fiscal model for the award of hydrocarbon acreages towards exploration and production (E&P).
  • HELP is applicable for all future contracts to be awarded.
  • HELP replaces the present policy regime for exploration and production of oil and gas, known as New Exploration Licensing Policy (NELP), which has been in existence for 18 years.

Features of HELP:

• Uniform License: It provides for a uniform licensing system to cover all hydrocarbons such as oil, gas, coal bed methane etc. under a single licensing framework, instead of the present system of issuing separate licenses for each kind of hydrocarbons.
• Open Acreages: It gives the option to a hydrocarbon company to select the exploration blocks throughout the year without waiting for the formal bid round from the Government.
• Revenue Sharing Model: Present fiscal system of production sharing contract (PSC) is replaced by an easy to administer “revenue sharing model”. The earlier contracts were based on the concept of profit sharing where profits are shared between the Government and the contractor after recovery of cost.
• Marketing and Pricing Freedom: It has been granted, subject to a ceiling price limit, for new gas production from Deepwater, Ultra-Deepwater and High Pressure-High Temperature Areas.

Explanation:

• Both statement 1 and 2 is Incorrect: Pradhan Mantri Sahaj Bijli Har Ghar Yojana – ‘Saubhagya’ a new scheme was launched by the Ministry of Power. Under Saubhagya free electricity connections to all households (both APL and poor families) in rural areas and poor families in urban areas will be provided. There are around 4 Crore un-electrified households in the country and they are targeted for providing electricity connections by December 2018.  Rural Electrification Corporation (REC) has been designated as its nodal agency for the Saubhagya scheme.

Explanation:

• Coal Bed Methane, also known as a Coal Seam Gas(CSG), is an unconventional form of natural gas found in coal deposits.
• Advantages:
  • High calorific value
  • Contains 95 per cent pure methane and is hence a good fuel
  • Does not contain harmful gases like H₂S
  • Environment-friendly when compared with other conventional sources of energy
• Disadvantages:
  • Methane, being a greenhouse gas, becomes a matter of concern, keeping in the view the emissions from coal mines.
  • Drilling of land for the extraction of CBM results in acute eco-systems damage
  • Wildlife habitats are disturbed.
  • Extraction of CBM involves disposal of highly salinised water, whose introduction to freshwater eco-system poses a serious threat to the aquatic environment

Explanation:

• Waste-to-Energy (WtE) or Energy-from-Waste (EfW) is a form of energy recovery and the process of generating energy in the form of electricity and/or heat from the primary treatment of waste, or the processing of waste into a fuel source. Waste to Energy methods which convert the energy into liquid or gaseous fuels as follows:
  • Gasification: Produces combustible gas, hydrogen, synthetic fuels
  • Thermal depolymerization: Produces synthetic crude oil, which can be further refined
  • Pyrolysis: produces combustible tar/bio-oil and chars
  • Plasma arc gasification or plasma gasification process (PGP): Produces rich syngas including hydrogen and carbon monoxide usable for fuel cells or generating electricity to drive the plasma arch, usable vitrified silicate and metal ingots, salt and sulphur.

Explanation:

• Option A is the Correct Answer:
  • First-generation Biofuels - First-generation biofuels are made from sugar, starch, vegetable oil, or animal fats using conventional technology. Common first-generation biofuels include Bioalcohols, Biodiesel, Vegetable oil, Bioethers, Biogas.
  • Second-generation Biofuels - These are produced from non-food crops, such as cellulosic biofuels and waste biomass (stalks of wheat and corn, and wood). Examples include advanced biofuels like biohydrogen, bioethanol.
• Third-generation Biofuels - These are produced from micro-organisms like algae.
• Fourth Generation Biofuels - In the production of these fuels, crops that are genetically engineered to take in high amounts of carbon are grown and harvested as biomass.