• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The purpose of this lab is to prove the discovery of George Ohm, that when the temperature of a metallic conductor is kept constant, the current through the conductor is proportional to the potential difference across it.

Extracts from this document...

Introduction

Lab No. 4

Current

Proving Ohm’s Law

By: Rendol Williams

Mr. Smith

Irmo High School

4A Physics SL

Friday, January 27, 2012

  1. DESIGN

  1. Introduction

The purpose of this lab is to prove the discovery of George Ohm, that when the temperature of a metallic conductor is kept constant, the current through the conductor is proportional to the potential difference across it. This statement is known as Ohm’s Law. It is represented in the equation V=IR. By manipulating the elements of Ohm’s Law students will be able to test the validity of Ohm’s Law. The elements which include Voltage measured in volts, Current measured in amperes and Resistance measured in Ohms. Voltage in a circuit is the force that pushes the electrons along the path. Current this is the amount of charge per unit time that passes through the cross-sectional area of a conductor. Lastly resistance is the ratio of voltage across a conductor to the current through it. A series circuit is a circuit containing only one electron path or e-path for the electrons to move across.

...read more.

Middle

DATA COLLECTION AND PROCESSING
  1. Raw Data

Circuit Type

Voltage

(V)

Current

(mA)

Accepted Resistance (Ω)

Single

0 V

1.5 V

2.2 V

3.0 V

4.5 V

0 mA

5.5 ± .5 mA

8.2 ± .5 mA

11.3 ± .5 mA

16.7 ± .5 mA

250 Ω

Series

0 V

1.5 V

2.2 V

3.0 V

4.5 V

0 mA

2.5 ± .5 mA

3.5 ± .5 mA

5.0 ± .5 mA

7.0 ± .5 mA

600 Ω

Parallel

0 V

1.5 V

2.2 V

3.0 V

4.5 V

0 mA

25.0  ± 1 mA

37.0  ± 1 mA

50.0 ± 1 mA

73.5 ± 1 mA

55 Ω

Complex

0 V

1.5 V

2.2 V

3.0 V

4.5 V

0 mA

6.5 ± .5 mA

9.5 ± .5 mA

12.5 ± .5 mA

18.5 ± .5 mA

225 Ω

...read more.

Conclusion

  1. Evaluation (ASPECT 2)

There were many clear errors that were found in this experiment. There was the random error of resistance being contained in the ammeter that was from old wires or some unknown force. This resultantly gave us skewed results on the actual amount of current running through the circuit. Another error was the systematic error of the reader reading the value of the current. The problem of parallax occurred as the perspective of different students led to different results and a larger uncertainty which leads to a decreased amount of accuracy. The final error we observed was that the alligator clips contained resistance within them and thus skewed the results.

  1. Improvements (ASPECT 3)

We can fix these problems by simply making a few alterations to the experiment. In regard to the problem of parallax a digital form of an ammeter would surely eliminate this issue. We can fix the error of resistance in the alligator wires and the ammeter by finding a better form of conductor that offers a less noticeable form of resistance on the circuit system.

...read more.

This student written piece of work is one of many that can be found in our International Baccalaureate Physics section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Physics essays

  1. Aim: To prove the parallelogram law of vector addition

    It could also be caused by existence of friction between the string and the pulley wheel which is not taken into account here. Errors could also be caused when we are using a protractor to measure the angle between the two forces.

  2. Finding the Spring Constant

    This tells us that our results were very good as we obtained a well straight line. We can comment on the correlation as well where we can state it was quite accurate as the R� value was 0.997 which indicates a good correlation in the graph.

  1. The purpose of this lab is to examine impact craters. Impact craters occur when ...

    Sandbox With No Water Height (cm) or () 50.00 14.63 3.25 60.00 14.81 3.29 70.00 14.96 3.31 80.00 15.10 3.35 90.00 15.21 3.39 The equation of the linearization is This graph keeps in mind the error and uncertainty. Sandbox With 350 mL of Water Height or ()

  2. Ohm's Law lab

    For Ohmic resistors, V=IR Where V= Drop in Voltage, I = Current, R = Resistance. DCP Graph 1.1 - Graph showing the plotted readings for the bulb filament immersed in water with the ammeter reading (A) on the y-axis and the voltmeter reading on the x-axis and line of best fit.

  1. Pendulum Lab

    Force- The force imparted on the pendulum will change the velocity and thus the period of the pendulum. In this experiment no force was imparted on the bob during the trials, the only force present was gravity which was constant throughout the experiment.

  2. Resistance Lab. Aim - To investigate the effective resistance (total resistance) of ...

    across all three resistors and all three voltmeters (as shown above). 2) Now set the current in the circuit to 150 milliamps using the power pack and the ammeter. 3) Quickly take the readings for the voltage across each individual resistor (V1, V2 and V3)

  1. HL Physics Revision Notes

    An ideal voltmeter has an infinite resistance. A potential divider is an electric circuit with a cell and two resistors in series. It is called so because the resistors divide up the potential difference of the battery. A light dependent resistor (LDR) is a device whose resistance depends on the amount of light shining on its surface.

  2. Experiment to show the application of Kirchhoffs Voltage Law & Kirchhoffs Current Law in ...

    This idea by Kirchoff is known as the Conservation of Energy. ________________ Theory Kirchoff?s first law state that total current or charge entering a junction or node is exactly equal to the charge leaving the node, so: ?Iin = ?Iout Graphically, Here, the 3 currents entering the node, I1, I2,

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work