# Ohm’s Law

**Purpose: To verify Ohm’s Law**

**Objectives**

- To learn how to measure current through and voltage across a resistor.
- To learn how to record experimental data using spreadsheet
- To learn how to plot, and analyze data using a spreadsheet.

**Equipment:**

- Two multimeters, breadboard, and a 2,000-Ohm Resistor
- Power supply

**Theory**

The relationship between the current through and the voltage across a resistor is given by Ohm’s Law

Here, the current *I* is given in amp, the voltage *V* is in Volt, and the resistance *R* is in Ω

**Preliminary Setup.**

Create a complete circuit using the power supply, one of the multimeters and the 2000-Ohm resistor on the breadboard.

**Warning! Make sure the multimeter is switched to current-measuring mode. The knob must point to the amps, or else you can blow the fuse. **

**Warning!** Make sure the voltage know of the power supply is turned down to zero before you turn it on.

Connect a voltmeter across the resistor.

**Activity 1.**

Measure the current through and voltage across the resistor.

Adjust the power supply so that the current through the resistor is 1 mA. Measure the voltage in Volts

**Activity 2.**

- Open Microsoft Excel Spreadsheet and type in your data. Make sure the current is recorded in A and not mA.
- Get the spreadsheet to calculate the resistance for you.
- Using excel, plot a graph Voltage versus Current I.

**Question: **Do you get a straight line?