# Electric currents, electric charges – problems and solutions

1. A steady current of 10 A exists in a wire for 2 minutes. How much the amount of charge that passes through the conductor at any location.

__Known :__

Electric current (I) = 10 A

Time interval (t) = 2 minutes = 2 x 60 seconds = 120 seconds

__Wanted :__ Charge (Q)

__Solution :__

Equation of the electric current :

I = q/t

*I = the electric current, q = the electric charge, t = the time interval*

The electric charge :

Q = I t = (10)(120) = 1200 C

2. 60 C of charge passes by a point in the circuit during 5 minutes. What is the electric current .

__Known :__

The time interval (t) = 5 minutes = 5 x 60 seconds = 300 seconds

The electric charge (Q) = 60 C

__Wanted :__ The electric current (I)

__Solution :__

The electric current :

I = Q/t

I = 60 / 300

I = 0.2 Coulombs/second

I = 0.2 Ampere

3. Unit of the electric current in SI system is…

Solution

Coulombs/seconds

Coulombs/seconds, given a special name, the Ampere.