The correct renewable sources of energy are :

(i) Biomass

(ii) Nuclear fuel

(iii) Coal

(iv) Petroleum

1. (i)
2. (iii)
3. (ii) and (iv)
4. (i) and (ii)

Geothermal energy is the energy possessed by the:

1. Sun
2. Wind
3. Biomass
4. Rocks

The chemical formula of the strong-smelling substance that is mixed in LPG is :

1. C₂H₂SH
2. C₂H₅SH
3. CH₅SH
4. C₂SH₃

The process used for refining of petroleum is known as:

1. evaporation
2. filteration
3. distillation
4. fractional distillation