Ohm’s Law Lab Report

Name: ______________________
Date: _______________________

Purpose: 
The purpose of this lab activity is to investigate the relationship between the voltage across a resistor and the current flowing through it.

Hypothesis: 
What effect will increasing the voltage in a circuit have on the current in the circuit?

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What effect will increasing the voltage in a circuit have on the brightness of a light bulb connected to the circuit?

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Materials:
In addition to this sheet and the multi-media element, you will require a calculator and graph paper.

Method:
The instructions for the activity are in the multi-media element itself. Be sure to record all necessary results as you are working through the lab activity.

Results:
Adjust the power source so that the voltmeter displays the values in the table below. Then enter the value displayed on the ammeter and comment on the brightness of the light bulb.
Voltage 	Current	Brightness of the light bulb	
0 V			
0.5 V			
1.0 V			
1.5 V			
2.0 V			
2.5 V			
3.0 V			
3.5 V			
4.0 V			
4.5 V			
5.0 V			
5.5 V			
6.0 V			

Analysis:
1.	Use the data to plot a voltage-current graph. (Hint: Voltage goes on the vertical axis.)
2.	Draw in the line-of-best-fit and find the slope of the line. Round off your answer to one decimal point. The slope of the line is equal to the resistance of the light bulb. Calculate the resistance of the light bulb.
3.	Compare your results to the prediction you made in your hypothesis.
4.	What is the resistance of the light bulb?

Conclusions:

1.	What effect does increasing the voltage have on the brightness of the light bulb?

2.	What effect does increasing the voltage have on the current?

3.	What happens to the current when the voltage is:

a)	doubled?

b)	tripled?