In KN sharma book (ISC) it is written that 4π lines of force originate from a unit positive charge .But then this gives different results than when we use Φ=q/ε it gives different results.Why is that?

This is a typical blunder committed by the author of a book meant for rote learning. your doubt will be easily cleared by any good iit-jee book,like resnick and halliday

that is correct but it has something to do with solid angle.

thanks for the answer