Question

Regarding the assertion and reason, choose the correct option:
Assertion [A]: Methane component of greenhouse gases contributes to global warming by about 20 percent.
Reason [R]: Introduction of multipoint fuel injection engines in automobiles has decreased methane content in exhausts.

• A. Both A and R are true and R is the correct explanation of A
• B. Both A and R are true but R is not the correct explanation of A
• C. A is true but R is false
• D. Both A and R are false

Answer 1

The correct option is B Both A and R are true but R is not the correct explanation of A

Carbon dioxide contributes to about 60% of the total global warming and the shares of methane and chlorofluorocarbons (CFCs) are 20% and 14% respectively. N₂O also contributes to about 6% of the total global warming. Efficient engines such as multipoint fuel injection engines can reduce the amount of unburnt hydrocarbon (methane) in auto-emissions, which can decrease the emission of these gases from automobiles.