Which of the following types of alcohol is used as a fuel in vehicles?

Biogas is composed of .......

Mohan was writing a report on the benefits of biogas:
$i$. It is cheap and safe
$ii$. Can be used for cooking
$iii$. Can be transported easily
$iv$. Causes pollution
Which one of the above statements has been reported incorrectly?

Which of the following is the rate-limiting factor in biogas production?

Methanogens,particularly $Methanobacterium$,grow anaerobically on cellulosic material and produce:
$I.$ Methane
$II.$ Carbon dioxide
$III.$ Oxygen
$IV.$ Ethane
Choose the correct option.

In $STPs$,in which tank is biogas produced during the process?