Introduction to Ohm's Law


At the end of this module, you will be able to calculate the relationship between resistance, voltage and current using Ohm's Law.


Textbook: DC/AC Principles: Analysis and Troubleshooting - Chapter 3 Ohm's Law


Ohm's Law provides a simple mathematical relationship between Resistance, Current and Voltage.

The relationship is expressed as:

V = I x R



A Series Circuit has a current I = 10 mA flowing through a resistor R1 = 5 Kohm. What is the voltage of the Voltage Source Vs ?

Using Ohm's Law:

V = I x R

We can substitute the values for the current I and the resistance R1 in the above equation.

V = 10 mA x 5 Kohms = 50 Volts


1. True or False

Ohm's Law provides a simple mathematical relationship between Voltage, Current and Resistance in an electric circuit.

2. Ohm's Law states that:

3. What would be the effect on the current flowing through a resistor if the resistance increased while the voltage remained constant?

4. If the applied voltage Vs is 85 Volts and R1 = 9 Kohm, solve for the circuit current:

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