Assertion (A) : The efficient of a boiler is more if it is provided with mechanical draught rather than with natural draught
Reason (R) : The exhaust gases can be cooled to the lowest possible temperature if mechanical draught is provided
Option (A)
Both A and R are individually true and R is the correct explanation of A
Option (B)
Both A and R are true but R is not the correct explanation A
A is true but R is false
A is false but R is true
Correct Option:
Question Solution:
With mechanical draught high operating efficiency (about 70%) then that of natural draught (about 1 %). Since about 20% of heat generated is lost in flue gases, low temperature of flue gases reduced energy lost in the flue gases