Hemant visited his neighboring village, where a bio-gas plant has been installed recently. He was surprised to see the working of the bio-gas plant. He told his village elders about the advantages of setting up a bio-gas plant in their village. Now. Answer the following question:
(i) What are the advantages of a biogas plant?
(ii) Why is a bio-gas plant commonly called as gobar gas plant?
(iii) Why were the villagers are very much impressed with Hemant?