Electronic circuits involve the manipulation of voltages, currents, and resistances. Knowing how these three properties relate to each other is a foundational part of circuit design. These relationships are described using the equation, **Ohm’s Law**.

The formula of Ohm’s Law is as follows:

`$V = I × R$`

Where:

- V = voltage expressed in Volts
- I = current expressed in Amps
- R = resistance expressed in Ohms

*Note: Voltage is sometimes represented in Ohm’s Law using “E”*

If two values are known, we can use algebra to reconfigure Ohm’s Law and calculate the third value:

To find the current, divide volatge by resistance.

`$I = V ÷ R$`

To find resistance, divide voltage by current.

`$R = V ÷ I$`

The above schematic has a voltage source with an unknown voltage. There is a current, **I = 2A** through a load resistor, **R = 4.5Ω**. Using Ohm’s Law we can find the voltage of the circuit’s voltage source:

`$V = I × R$`

`$V = 2A × 4.5Ω$`

`$V = 9V$`

The above example contains one voltage source and one load resistor. In general, a circuit’s load will consist of multiple components. In this case, you will need to find out how much of the source voltage is used by each component when applying Ohm’s Law.

### Instructions

**1.**

Use the given values in Circuit 1 and Ohm’s Law to find the voltage (V) across the voltage source.

Type your answer below `Answer 1`

. It should look like `V = your answer`

**2.**

Use the given values in Circuit 2 and Ohm’s Law to find the current (I) through the circuit.

Type your answer below `Answer 2`

. It should look like `I = your answer`

**3.**

Use the given values in Circuit 3 and Ohm’s Law to find the resistance (R) of the resistor.

Type your answer below `Answer 3`

. It should look like `R = your answer`