The value of solar constant is

1. 1.34 kW km^-2
2. 1.34 kW m^-2
3. 1.34 kW m²
4. none of the above

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)

The main constituent of biogas is :

1. oxygen
2. carbon dioxide
3. nitrogen
4. methane

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

1. C₂H₂SH
2. C₂H₅SH
3. CH₅SH
4. C₂SH₃