Question : Sentences of a paragraph are given below. While the first and the last sentences ( 1 and 6) are in the correct order, the sentences in between are jumbled up (A to D). Arrange the sentences in the correct order to form a meaningful and coherent paragraph.

1. Biogas is a mixture of methane, carbon dioxide and hydrogen with others.
A. Biogas is produced by anaerobic degradation of animal wastes (some plant wastes) in presence of water.
B. Thus, biogas is a non-polluting, cleaned and low cost fuel.
C. Anaerobic degradation means breakdown of organic matter which is done in the absence of oxygen.
D. It is mostly used in rural areas where ample animal and agricultural waste is available.
6. Biogas eliminates the risk of health hazards offered by other fuels.

Option 1: DABC

Option 2: CBDA

Option 3: ACBD

Option 4: BDAC

Question : When Hydrogen starts burning in air ,it produces?

Option 1: Ammonia

Option 2: water

Option 3: Methane

Option 4: Carbon dioxide

Question : Which one of the following statements about pyrolysis, which is a process for solid waste treatment, is incorrect?

Option 1: It converts the waste into solids, liquids and gases, of which the resultant liquids and gases can be used to produce energy.

Option 2: The process occurs at a temperature above 430^oC at atmospheric pressure.

Option 3: The process occurs under high pressure at a temperature above 430^oC.

Option 4: It is a thermochemical decomposition of organic waste.

Question : Production of alcohol from organic compound by microorganisms is known as:

Option 1: combustion

Option 2: fermentation

Option 3: anaerobic respiration

Option 4: aerobic respiration

Question : How many hydrogen atoms are there in a molecule of methane?

Option 1: 2

Option 2: 6

Option 3: 4

Option 4: 3