How long must a current of 100ma flow so as to transfer a charge of 80c

800 s

Explanation:

This can be solved using the equation:

I = Q/T where

I is the amount of current in A

Q is the amount of charge in C

T is the duration in s.

Hence by substituting the values, we get:

100 * 10^-3 = 80/T

T = 80 / 100 * 10^-3

T = 800 s

(Note: When substituting I, remember to change from mA to A)