Nuclear fuels<\/li>\n<\/ul>\nFossil fuels are present in a limited. amount in the earth. Once exhausted, they will not be available to us again. It takes millions of years for fossil fuel to be formed. The nuclear materials which can be conveniently extracted from earth 7. are limited and hence they will get exhausted one day.<\/p>\n
KSEEB SSLC Class 10 Science Chapter 14 Textbook Exercises<\/h3>\n
Question 1.
\nA solar water heater cannot be used to get hot water on
\n(a) a sunny day
\n(b) a cloudy day
\n(c) a hot day
\n(d) a windy day
\nAnswer:
\n(b) a cloudy day.<\/p>\n
Question 2.
\nWhich of the following is not an example of a bio-mass energy source?
\n(a) wood
\n(b) gobar-gas
\n(c) nuclear energy
\n(d) coal
\nAnswer:
\n(c) nuclear energy.<\/p>\n
Question 3.
\nMost of the sources of energy we use represent stored solar energy. Which of the following is not ultimately derived from the Sun\u2019s energy?
\n(a) geothermal energy
\n(b) wind energy
\n(c) nuclear energy
\n(d) bio-mass.
\nAnswer:
\n(b) wind energy.<\/p>\n
Question 4.
\nCompare and contrast fossil fuels and the Sun as direct sources of energy.
\nAnswer:
\nAir pollution is caused by burning of coal or petroleum products. The oxides of carbon, nitrogen and sulphur that are released on burning fossil fuels are acidic oxides. These lead to acid rain which affects our water and soil resources. In addition to the problem of air pollution, recall the green house effect of gases like carbon dioxide.<\/p>\n
Sun is the main source Of energy, we get all sources of energy by solar energy. Hence this a renewable source of energy which we get in plenty and free of cost.<\/p>\n
Question 5.
\nCompare and contrast bio-mass and hydro electricity as sources of energy.
\nAnswer:
\nBio-mass: Cow-dung, various plant materials like the residue after . harvesting the crops, vegetable waste and sewage are decomposed in the absence of oxygen to give biogas. Since the starting material is mainly cow-dung, it is popularly known as \u2018gober gas\u2019. Biogas is produced in biogas plant.<\/p>\n
Bio gas is an excellent fuel as it contains up to 75% Methane. It burns without smoke, leaves no residue like ash in wood, charcoal and coal burning. The slurry left behind is removed periodically and used as excellent manure. This is one of the renewable source of energy.<\/p>\n
Hydro Electricity: In order to produce hydel electricity, high rise dams are constructed on the river to obstruct the flow of water and thereby collect water level rises and in this process the kinetic energy of flowing water, gets transformed into potential energy. The water from the high level in the dam is carried through pipes to the turbine, at the bottom of the dam. Since the water in the reservoir would be refilled each time it rains. We would not have to worry about hydro electricity sources getting used up the way fossil fuels would get finished one day.<\/p>\n
Question 6.
\nWhat are the limitations of extracting energy from\u2014
\n(a) the wind?
\n(b) waves?
\n(c) tides?
\nAnswer:
\n(a) The wind:<\/p>\n
\n- Wind energy farms can be established only at those places where wind blows for the greater part of a year.<\/li>\n
- The wind speed should also be higher than 15 km\/h to maintain the required speed of the turbine.<\/li>\n
- Establishment of wind energy farms require large are of land.<\/li>\n<\/ol>\n
These are the limitations of extracting energy from the wind.<\/p>\n
(b) Limitations of extracting waves energy: The waves are generated by strong winds blowing across the sea. Wave energy would be a viable proposition only where waves are very strong.<\/p>\n
(c) Limitations of extracting tidal energy: The locations where such dams can be built are limited.<\/p>\n
Question 7.
\nOn what basis would you classify energy sources as
\n(a) renewable and non-renewable?
\n(b) exhaustible and inexhaustible?
\nAre the options given in (a) and (b) the same?
\nAnswer:
\nThe options given in (a) and (b) are the same.<\/p>\n
Question 8.
\nWhat are the qualities of an ideal source of energy?
\nAnswer:
\nThe qualities of an ideal source of energy are as follows:<\/p>\n
\n- Which would do a large amount of work per unit volume or mass.<\/li>\n
- Be easily accessible.<\/li>\n
- Be easy to store and transport, and<\/li>\n
- Perhaps most importantly, be economical.<\/li>\n<\/ol>\n
Question 9.
\nWhat are the advantages and disadvantages of using solar cooker? Are there places where solar cookers would have limited utility?
\nAnswer:
\nSolar cookers have limited utility at places which remain cloudy or have larger winters eg, hilly areas. Advantages of using a solar cooker<\/p>\n