CBSE Class 10 Science Chapter-14 Sources of Energy – Free PDF Download
Free PDF download of Important Questions with Answers for CBSE Class 10 Science Chapter 14 – Sources of Energy prepared by expert Science teachers from latest edition of CBSE(NCERT) books only by CoolGyan to score more marks in CBSE board examination.
CBSE Class 10 Science Chapter-14 Sources of Energy Important Questions
CBSE Class 10 science Important Questions Chapter 14 – Sources of Energy
5 Mark Questions
1. A student constructed a box type solar cooker. He found that it did not work efficiently. What could this be due to? Give any four possible mistakes in the construction and operation of the solar cooker. What maximum temperature can ordinarily be reached inside a solar cooker?
Ans. He might have committed some mistakes.
(i) Interior of the solar cooker not painted in black colour.
(ii) Instead of glass sheet, plastic sheet is used to cover it.
(iii) Solar cooker is without insulation.
(iv) Black containers have not been used.
Maximum temperature is 
b in solar cooker.
2. (i) What is biogas? Name two main combustible components of biogas?
(ii) What is the use of spent slurry in a biogas plant?
(iii) Name the microorganisms responsible for the fermentation of slurry in the digester?
Ans. (i) Biogas is a mixture of various gases formed when the animal dung mixed with water is allowed to decompose in the absence of air. The two combustible component of biogas are 
gas.
(ii) The spent slurry in biogas plant is rich in nitrogen and phosphorous required for the growth of plants and hence can be used as a manure.
(iii) Anaerobic micro- organism.
3. What are the limitations of extracting energy from:
(i) the wind? (ii) waves? (iii) tides?
Ans. (i) The Wind:
(a) It is not available at all times.
(b) It requires a very large area of land.
(c) It is not possible to have a windmill everywhere as to run it, the minimum wind speed of 15 km/hr is required (only possible in open areas like the seaside).
(ii) Waves:
(a) Wave energy would be a viable proposition only where waves are very strong.
(b) It is costly to set up devices to trap wave energy.
(iii) Tides:
(a) Very few sea coasts in the world have suitable sites for the purpose of harnessing tidal energy.
(b) The rise and fall of tides happen only twice in a day is not sufficient to generate electricity continuously.
4. On what basis would you classify energy sources as
(a) renewable and non-renewable?
(b) exhaustible and inexhaustible?
Are the options given in (a) and (b) the same.
Ans. (a) Renewable sources of energy are those sources which can be regenerated again. Non-renewable sources of energy are those sources which would get depleted some day and cannot be regenerated.
(b) Exhaustible sources of energy are those which will be exhausted some day and cannot be regenerated. Inexhaustible sources of energy are those which can be regenerated again due to some continuing or repetitive currents of energy and are inexhaustible.
Options in both cases are exactly same.
5. What are the advantages and disadvantages of using a solar cooker? Are there places where solar cookers would have limited utility?
Ans. Advantage of solar cooker:
a. There is no cost of fuel.
b. It is environment friendly and there is no residue like ash etc.
c. Cooking is hygienic and nutritious.
Disadvantage of solar cooker:
a. The cooking is slow.
b. It cannot be used at all times.
c. A solar cooker can perform only limited functions.
6. What are the environmental consequences of the increasing demand for energy? What steps would you suggest to reduce energy consumption?
Ans. The increasing demand for energy is largely being met by the use of fossil fuels. But these fuels are exhaustible and non-renewable sources of energy. Moreover, burning of fossils fuels cause air pollution. Release of acidic oxides leading to acid rain that affect our water and soil resources. These gases also produce greenhouse effect leading to increase the temperature of earth. To reduce energy consumption we should lead a simple and a natural life. As an example, instead of using an air conditioner in a closed room we should live in an airy room having appropriate number of windows.
