All exercise S.Qs of Energy for the book Science of Global Challenges. We have gathered all S.Qs for BS/MSc Physics.
Q.1 Why fossils fuels are called non-renewable form of energy?
Answer: Fossil fuels are called “non-renewable” because we are consuming them faster than they are created. Coal, for instance, is created over geological time periods (>106 years), and we will likely consume most (> 90%) of it in less than 1,000 years. Fossil fuels are a finite resource. The faster we use them, the less time we have them available to use.
Q.2 Which form of energy is most preferred and why?
Answer: Generally, in now-a-days the solar energy is the most preferred and needed one for all the people in the world. Since all the people in the world can get sunlight throughout the year it is wise to install solar power generator in the houses, offices and factories which is of low cost, easy maintenance and the people can get the electricity throughout the year without any interruption during winter days people don’t need to worry they can save the excess energy in the batteries during the summer season and they can use it in the winter season which will be a cost effective one If we are able control the fusion reactions, then nuclear energy is the most-preferred form of energy otherwise solar energy is preferable. The most familiar form of energy is chemical energy also the preferred form of energy is the renewable energy (Green Energy) because it is the cheapest to be generated with minimum environment pollution.
Q.3 How energy converted from one form to another? Explain.
Answer: energy can neither be created and nor be destroyed but can be transformed from one form to another. Now talking about your example in a typical light bulb electrical energy is converted into light energy and heat energy.
Q.4 How electrical energy can be obtained from sunlight by indirect conversion method?
Answer: Solar radiation may be converted directly into electricity by solar cells (photovoltaic cells). In such cells, a small electric voltage is generated when light strikes the junction between a metal and a semiconductor (such as silicon) or the junction between two different semiconductors.
Q.5 How energy can be get from waves?
Answer: Depending on the lunar cycles, tides, winds, and weather, waves can vary in size and strength. As waves roll through the ocean, they create kinetic energy, or movement. This movement can be used to power turbines, which, in turn, create energy that can be converted into electricity and power. here are also several ways of harnessing wave energy that utilize the up and down motion of the waves to power pistons/turn generators.
Q.6 What is geothermal energy? How it is generated.
Answer: Geothermal energy is a type of renewable energy taken from the Earth’s core. It comes from heat generated during the original formation of the planet and the radioactive decay of materials. This hermal energy is stored in rocks and fluids in the center of the earth.
Q.7 What is hydrogen energy? Explain.
Answer: Hydrogen, like electricity, is an energy carrier that must be produced from another substance. hydrogen can be produced-separated-from a variety of sources including water, fossil fuels, or biomass and used as a source of energy or fuel. Hydrogen has the highest energy content of any common fuel by weight (about three times more than gasoline), but it has the lowest energy content by volume (about four times less than gasoline). It takes more energy to produce hydrogen (by separating it from other elements in molecules) than hydrogen provides when it is converted to useful energy. However, hydrogen is useful as an energy source/fuel because it has a high energy content per unit of weight, which is why it is used as a rocket fuel and in fuel cells to produce electricity on some spacecraft. Hydrogen is not widely used as a fuel now, but it has the potential for greater use in the future.
Q.8 Differentiate between geyser ad aquifer.
Answer: Aquifer: It is a underground layer of water bearing permeable rock, rock fractures or unconsolidated materials. Geyser: It is a hot spring in which water intermittently boils, spending a tall column of water and steam into the air.
Q.9 What is carbon capture and storage?
Answer: the process of trapping carbon dioxide produced by burning fossil fuels or other chemical or biological process and storing it in such a way that it is unable to affect the atmosphere.
Q.10 What do you mean by carbon foot print.
Answer: A carbon footprint is the total amount of greenhouse gases (including carbon dioxide and methane) that are generated by our actions. The average carbon footprint for a person in the United States is 16 tons, one of the highest rates in the world.
