# Notes And Questions For NCERT Class 10 Science Sources of Energy

Students should refer to the below Sources of Energy Class 10 notes prepared as per the latest curriculum issued by CBSE and NCERT. These notes and questions are really useful as they have been developed based on the most scoring topics and expected questions in upcoming examinations for Class 10. Sources of Energy is an important topic in Science Class 10 which if understood properly can help students to get very good marks in class tests and exams.

Read the notes below which will help you to understand all important and difficult topics in this chapter. There are some topics in Sources of Energy chapter which you should understand carefully as many questions can come from those parts. Our team of teachers have designed the revision notes so that its helpful for students to revise entire course prior to the class tests.

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

Ans. 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?
Ans – Solar cooker with covered glass slab, as it will show green house effect.

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?
Ans – B, Maximum velocity required is 15km/h. At lower speed it will not work. At very high speed it may break the blades.

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

Question: How difference in temperature helps to harness energy from ocean?
Ans – 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: Give two ways in which animal dung can be used as fuel. Which way is better and why?
Ans – As dung cake and as Biogas.. Biogas is better because it spreads less pollution and has more calorific value.

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

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

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