CBSE Class 10 Science Sources of Energy Assignment Set C

Question : In the given flow chart of energy conversion during hydroelectric power generation,fill in the blanks with appropriate answer

Answer : Dynamo.

Question : Consider two solar cooker, one covered with a plane glass plate and other kept open. Which of the two cooker would be more efficient and why?
Answer : Solar cooker with covered glass slab, as it will show green house effect.

Question : Give one reason how increasing depandance on nuclear power generation is a threat for future generation?
Answer : Radiation emitted during leakage can change the genetic arrangement or disposal to nuclear waste.

Question : Give two ways in which animal dung can be used as fuel. Which way is better and why?
Answer : As dung cake and as Biogas.. Biogas is better because it spreads less pollution and has more calorific value.

Question : The wind velocity at three places A,B and C are 5Km/hr,15Km/hr,10Km/hr respectively. Which is the most suitable place for installing wind mill & why?
Answer : B, Maximum velocity required is 15km/h. At lower speed it will not work. At very high speed it may break the blades.

Question : What are two advantages of charcoal over wood as fuel?
Answer : High calorific value & pollution free

Question : How difference in temperature helps to harness energy from ocean?
Answer : The difference in temperature helps to obtain energy in ocean- thermal – energy conservation plants, which operate for temperature difference of 20о C or more. The warm surface water is used to boil a volatile liquid . The vapours of the liquid are used to run the turbine of generator , the cold water from the depth of the ocean is pumped up and condense vapour again to liquid.

Question : Mention any two reasons, why wood is not preferred as fuel.
Answer : (i) Burning wood causes pollution
-(ii)Excess use of wood would cause deforestation.

Question : Write three reasons why construction of Tehri Dam on river Ganga and Sardar Sarovar project on river Narmada is opposed by local people and environmentalist?
Answer : (i) Rehabilitation problems, loss of agricultural land.
(ii) Disturbance of ecological balance.
(iii) Forming of green house gases due to decomposition of plant in water.

Question : Write three environmental consequences of the various source of energy we used?
Answer : Green house effect, improper use of natural resources, pollution.