The question asks for the primary reason behind promoting renewable energy sources. This requires understanding the core benefits and motivations for transitioning away from conventional energy.
Correct Option: B) To reduce environmental damage
Promoting renewable energy sources is fundamentally driven by the need to combat climate change, reduce air pollution, and protect ecosystems, all of which fall under the umbrella of reducing environmental damage. Fossil fuels are a major contributor to greenhouse gas emissions and other pollutants.
The question asks to identify the correct statements comparing CFL (Compact Fluorescent Lamp) and LED (Light Emitting Diode) lamps based on their light production mechanism, lifespan, and energy efficiency. We need to evaluate each statement individually.
C) 1 and 3 only
Statements 1 and 3 are correct, while statement 2 is incorrect. Therefore, option C is the correct answer.
The question asks to identify the correct statements regarding why microbial fuel cells (MFCs) are considered a source of sustainable energy. We need to evaluate each statement based on the principles and applications of MFCs.
C) 1 and 3 only
Statement 1 is correct because MFCs indeed use living organisms (microbes) as catalysts to produce electricity from various substances. Statement 3 is correct because MFCs have a significant application in wastewater treatment, where they can simultaneously clean water and generate electricity, making them a sustainable technology.
The question asks to identify which option is NOT a primary renewable energy source. We need to understand the definition of renewable and non-renewable energy sources.
Based on these evaluations, coal is the option that is not a primary renewable energy source.
Correct Option: D) Coal is a fossil fuel, which is a non-renewable energy source. It takes millions of years to form and is depleted much faster than it can be naturally replenished.
The question asks us to identify the correct statements regarding biomass gasification, specifically in the Indian context. We need to evaluate each statement based on the principles and applications of biomass gasification.
A) 1 only. Based on the evaluation, only statement 1 is correct.
The question asks about the usefulness of by-products of the sugar industry, specifically bagasse and molasses. We need to evaluate each statement to determine its correctness based on common industrial applications.
Bagasse is the fibrous residue left after crushing sugarcane stalks to extract juice. It is rich in cellulose and hemicellulose, making it an excellent biomass fuel. Sugar mills often burn bagasse to generate electricity and steam for their own operations, and sometimes even export surplus power to the grid. This statement is correct.
Molasses is a viscous by-product from the refining of sugarcane or sugar beets into sugar. While molasses is rich in carbohydrates and some minerals, it is primarily used in fermentation processes, animal feed, and ethanol production. It is not a direct feedstock for the production of synthetic chemical fertilizers. Synthetic chemical fertilizers (like urea, DAP, NPK) are typically produced from natural gas, air (for nitrogen), and phosphate rock. This statement is incorrect.
Molasses is a primary and widely used feedstock for the production of ethanol through fermentation. The high sugar content in molasses makes it ideal for yeast fermentation, which converts sugars into ethanol and carbon dioxide. This statement is correct.
Based on the evaluation:
Therefore, the correct combination of statements is 1 and 3.
C) 1 and 3 only — This option correctly identifies that bagasse is used as biomass fuel and molasses is used for ethanol production.