When resistors are connected in series, the combination has an equivalent resistance that is the sum of the resistances of the individual resistors. This property can be useful in creating desired resistance values from a limited selection of fixed resistors. The user will create a 9 kΩ resistor from the resistors available in the Digilent's® Analog Parts Kit.
Series circuit elements share the same current. Elements in series can be recognized in two ways: If two and only two elements are connected to a single node, the elements are in series. If applying KCL at a node results in the conclusion that the currents in two elements are identical, the elements are in series.
If the total voltage difference across a set of series resistors is known, there is an easy way to determine the voltage across any individual resistor in the series combination. The appropriate formula is called the voltage divider formula, since the total voltage is divided among the individual resistors.
When resistors are connected in series, a simplification of the circuit is possible.
In this project, we will expand our understanding of resistors in series by finding three fixed resistors—when combined in series, they will provide a specified resistance.
In this design challenge, we will build a circuit with a 5V source, 6.8 kΩ, and an arbitrary resistor. We will use the concept of voltage division to determine the resistance value of the arbitrary resistor when given a specific voltage drop across it.