Ohms Law Project

Ohm’s Law Project Instructions On the following four pages you will see a student’s handwritten experiment write-up for Ohm’s Law. A diagram had to be drawn – procedure written out – data entered – graph drawn – slope calculated and conclusion drawn. The final two pages show the exact same write-up done by computer. In any university course, experiment write-ups need to be professionally produced i.e. using a computer. This project requires you to produce a Microsoft Word document identical to the final 2 pages of this document i.e. a professional write-up. Open Microsoft Visio. Select Electrical Engineering shapes box – Basic Electrical (US units). Draw the diagram for the experiment – including all labels. Save the diagram into your own folder on the server – use the name Ohms Law Project Diagram.vsd SELECT the entire diagram and use SHIFT+CTRL+G to group it together. COPY this to the clipboard. Open Microsoft Word and set all margins to 0.8”. PASTE the diagram into it. Use the PICTURE TOOLBAR to set the text wrapping to TOP AND BOTTOM. Type in the Title and Date. Under the Date leave a blank line and enter the following…(using your name) Name:

Your Name

Type in the procedure and put the results into a 9x2 table. Open Microsoft Excel and use it to draw the straight line graph making sure that the equation of the line is displayed. Select the graph so that you can see the handles around it and then COPY it to the clipboard. Save the Excel worksheet into your folder on the server using the name Ohms Law Project Graph.xls PASTE the graph into your Word document and set the appropriate size and text wrapping. Finish typing the rest of the document. The Ω symbol can be inserted using the Insert Menu – Symbol – Times New Roman font – subset Basic Greek. When finished save the document into your own folder on the server using the name Ohms Law Project.doc Print the document – back and front on one sheet of paper – making sure you use print preview before you print to ensure that your document does not take up more than 2 pages. Show the printed document to your teacher and place it in your folder in the filing cabinet.

Title:

To verify Ohm’s Law for a metallic conductor at a constant temperature.

Date:

4th March, 2006

Ammeter A Metallic Conductor

Voltmeter

Battery

V

6V

Variable Resistor Procedure: 1. The apparatus was set up as shown in the diagram. 2. The variable resistor was set so as to give a small potential difference across the metallic conductor. 3. The voltage and current were noted. 4. The variable resistor was adjusted to give a slightly larger voltage. The current and voltage were again noted. 5. Step 4 was repeated six times. 6. The current and voltage values were tabulated. 7. A graph was drawn of voltage against current.

Results: V/V 0.547 0.884 1.597 2.051 2.466 3.081 3.662 4.053

I/A 0.125 0.203 0.361 0.467 0.552 0.698 0.831 0.921

Ohm's Law for a metallic conductor. y = 4.4137x - 0.0014

4.5 4 3.5

V/V

3 2.5 2 1.5 1 0.5 0 0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

I/A

From the graph the slope of the line was found to be = 4.41 ⇒

The resistance of the metallic conductor = 4.41Ω .

Conclusion: A straight line graph through the origin was found showing that the voltage is proportional to the current verifying Ohm’s Law. The slope of the graph was calculated to be 4.4. Since the resistance of the conductor is equal to the slope of the graph this implies that the resistance of the metallic conductor is 4.41Ω . Immersing the conductor in a water bath would ensure that its temperature remained constant. Not doing so would have given rise to a small error due to the temperature of the conductor increasing.