How can solar energy be harnessed? Mention any two limitations in using solar energy. How are these limitations overcome?
Which is the process used to harness nuclear energy these days? Explain it briefly.
What steps would you suggest to minimise environmental pollution caused by burning of fossil fuels?
Why is there a need to harness non-conventional sources of energy? Give two main reasons
Choose the incorrect statement
(a) We are encouraged to plant more trees so as to ensure clean environment and also provide bio-mass fuel
(b) Gobar-gas is produced when crops, vegetable wastes etc., decompose in the absence of oxygen
(c) The main ingredient of bio-gas is ethane and it gives a lot of smoke and also produces a lot of residual ash
(d) Bio-mass is a renewable source of energy