Ohm's Law

Design Challenge 3: Choosing Resistance

Ohm's Law:

Design Challenge 3: Choosing resistance


A common problem in designing electric circuits is having to pick a resistance that provides the desired amount of current. In this project, we will create a circuit (i.e. choose a resistor) which results in a specified current being provided by a 5V source.

This exercise uses concepts introduced in our experiment on Ohm's law. A link to this experiment is provided at the right.

Step 1

For the circuit shown below, choose a value for the resistor R so that the current I out of the source is between 10mA and 15mA. Your choice of resistors is limited to those available in the Digilent® Analog Parts kit.

Step 2

Construct the circuit above with the resistance value you determined in Step 1. Use your DMM to measure the current I.

Step 3

Compare the measured current with your expectations from Step 1. The current requirement should be between 10mA and 15mA. Did you meet this current requirement?

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