Ohm’s Law and Electric Circuit Diagram Practice Problems (V = IR)
1. Calculate the current flowing through the circuit of a toy car that has a resistance of 20Ω and is powered by a 3
volt battery. (show your work)
2. Calculate the voltage difference in a circuit with a resistance of 25 Ω if the current is 0.5 amps. (show your
work)
3. Calculate the voltage difference of a battery that is part of a circuit with a current of 2 amps. Also on the circuit
are a 2Ω resistor and a lamp that has a resistance of 1Ω. The resistor and lamp are in a series arrangement.
(show your work)
4. Draw an electrical circuit diagram for the circuit explained in question #3.
Use the electrical circuit diagram below to answer questions 5-7.
5. What is the total voltage difference of the batteries in the series arrangement?
6. What is the total amount of resistance in the circuit?
7. Calculate the current of the circuit using Ohm’s Law.
8. Use Ohm’s Law to complete the chart below.
I or electrical current (amps)
.5
V or voltage difference (volts)
10
9
1.5
.33
R or resistance (Ω)
10
2.5
10
9. Draw an electrical circuit diagram for each of the circuits described below.
# of Batteries
1
2
3
Voltage of
Batteries (v)
9
1.5
9
Battery Formation
(Series or Parallel)
S
S
P
Resistance of
Lightbulb
10
10
10
# of Resistors
(in series)
1
2
3
Resistance of
Resistors (Ω)
1
10
50