To reduce the possibility of knock in the C.I. engines, the first elements of fuel and air should have_______________?

A. has zero cetane number
B. has 100 cetane number
C. helps detonation
D. is a straight chain paraffin
E. determines the efficiency of an I.C. engine

Which of the following is false statement?
A. piston ring and cylinder wear
B. formation of hard coating on piston skirts
C. oil sludge in the engine crank case
D. detonation
E. forms corrosive acids

A. lower than the coldest atmospheric temperature at which oil is to be pumped
B. higher than above
C. has no such relation
D. more than 100°C
E. none of the above

A. high heat value
B. low heat value
C. net calorific value
D. middle heat value
E. calorific value

A. about twice
B. about 0.5 times
C. nearly equal
D. about 1.7 times
E. about 5 times