Electric Charge and Current Guided Practice Problems Formula: I=q/t

where I = current (in amps “A”)

q = charge (in Coulombs “C”)

t = time (in seconds “s”)

Note: The charge on an electron is – 1.60 x 10-19 C. 1.

An electrical device has 1.65 x 1056 electrons passing through it in 55 seconds. Calculate the electrical current that this device requires. Step 1 Determine total charge

2.

A lamp must have a current of 4.5 A in order to operate correctly. Calculate the number of electrons that must pass through the lamp in order for the lamp to work the way it suppose to work. Step 1 Determine the electric charge moving into the lamp

3.

Step 2 Determine the current

Step 2 Determine the number of electrons

A battery has 5.6 x 1098 electrons available to move through a circuit. Calculate how long in seconds a 2.5 A radio will play. Step 1 Determine the charge that the battery has available

Step 2 Determine the time the radio will play non-stop