A fuel is burned with 70% theoretical air. This is equivalent to a) 30% excess air, b) 70% excess air, c)70% deficiency air, d) 30% deficiency air, e) stoichiometric amount of air A fuel is burned with 70% theoretical air. This is equivalent to a) 30% excess air, b) 70% excess air, c)70% deficiency air, d) 30% deficiency air, e) stoichiometric amount of air Solution d) 30% deficiency air suppose, the theoretical amount is 100 gm of air, then the fuel burned is with 70 gm of the theoretical air, so air deficient = 100 - 70 gm = 30 gm , that is 30 % less air hence option D) is correct .