Question

How many electrons would have to be removed from a penny to leave it with a charge of 10
−
7
C

Answer 1

Answer:

6.25×10¹¹

Explanation:

Removing a certain number of electrons from a neutral body to produce a positive charge is the same as finding how many electrons constitute that charge. So, the number of electrons removed from a body in order to produce positive charge of 10⁻⁷ coulomb on it , will be the number of electrons constituting 10⁻⁷ coulomb of charge.

Now, one electron carries 1.6×10¹⁹ coulomb of charge.

So, 6.25×10¹⁸ electrons constitute 1 coulomb of charge.

∴ 6.25×10¹¹ electrons constitute 10⁻⁷ coulombs or charge and so 6.25×10¹¹ electrons must be removed from the penny for it to acquire the required charge.