Question

If 4.0 × 10^-18 J of work done on a point charge changes its electric potential difference by 25.0 V, then what is the magnitude of the charge?

Answer 1

Units must be known to solve this. 1V is the same as 1J/C. With this in mind, we can let the units guide us. By dividing the Work by the Electric Potential Difference, we will get the Charge in Coulombs.

(4.0 x 10^-18) / (25.0) = 1.6 x 10^-19 C

This is interesting for a problem! Because this is equal to the elementary charge e . So you could also say the magnitude of the charge is e.