If the protons and electrons are the only basic charges in the universe, all the observable charges have to be integral multiples of $e$. Thus, if an object contains $x$ electrons and $y$ protons, the net charge on the object will be
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → $(y-x) e$
Given:
Charge on one electron $= -e$
Charge on one proton $= +e$
If an object contains $x$ electrons and $y$ protons,
Then total charge,
$q = (+y e) + (-x e) = (y - x)e$
∴ Net charge on the object is $q = (y - x)e$