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

Ohm's Law Physics Lab #20

Extracts from this document...

Introduction

Ohm’s Law

Physics Lab #20

Name: Diana Abou Hassan

Partners: Sara Jaber

Michael Muhanna

Rami Jachi

Date Performed: 14/11/2002

Date Due: 21/11/2002

Teacher: Mrs. Khoury Saab

Objective:

The objective of this lab is to determine the relationship between the potential difference across a conductor and the electric current through it. \

Materials:

  • Low voltage variable DC power supply\
  • Two different resistors
  • 2 digital multimeters
  • connecting wires

Procedure: Please refer to lab sheet.

Data Collected:

Resistor 2

Voltage (V)

1

1.5

2

2.5

3

3.5

Current (mA + 0.01mA)

0.42

0.72

1.16

1.56

1.91

2.30

Potential Difference (V + 0.001V)

0.526

0.877

1.404

1.893

2.324

2.796

...read more.

Middle

2.359

2.793

Resistor 2 = 1.202 KΩ

Resistor 7 = 5.07 KΩ

Light Bulb

Before lighting up:

Voltage (V+ 0.0001V)

0.0069

0.0781

0.5780

0.6560

0.7590

Current (mA+ 0.01mA)

0.90

10.50

81.30

92.40

109.70

The light bulb lit up at:

Voltage (V+ 0.0001V)

1.0010

Current (mA+ 0.01mA)

149.30

After lighting up:

Voltage (V+ 0.0001V)

1.6090

1.8310

2.116

Current (mA + 0.01mA)

182.30

200.00

223.50

Data Analysis:

Calculate the slope of each graph:

Sample Calculation:

Slope of Resistor 2 = (y2 – y1) / (x2 – x1)

                                = (2.30 V – 0.42V )/(2.796mA – 0.526mA)

                                = (2.30 V – 0.42V )/(0.

...read more.

Conclusion

Sources of Error:

        The manual adjustment of the voltage may have caused some error as we may have not adjusted it to the exact values required. If there were a more detailed and precise knob, it could reduce the error. Also, the wire were very rusty therefore acting as very poor conductors. The obvious solution would be to use newer wires.  

Conclusion:

        The purpose of this lab was to see how the potential difference and the electric current going through a conductor are related. By graphing the results it showed that they were directly proportional. This proved to be correct also for the cold resistivity of the light bulb, however the resistivity of the light bulb after it lit up contradicted Ohm’s law as the resistivity did not remain constant.

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Electrical & Thermal 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 AS and A Level Electrical & Thermal Physics essays

  1. Marked by a teacher

    Determining Avogadro's Number Lab

    4 star(s)

    Thus, the average charge is approximately 570 C ±11.3%. Total charge = Sum of all 3 average charges Total charge = 540 C + 480 C + 570 C Total charge = 1590 C Absolute uncertainty of total charge = Absolute uncertainty of total charge = 192.51 The total charge is 1590 C ±192.5 C.

  2. Peer reviewed

    Measurement of the resistivity of Nichrome

    5 star(s)

    There are several possible sources of error and uncertainty in the experiment. 1. The most likely error might be reading the ammeter and voltmeter. As the voltage and current are always changing, it is hard to read precisely.

  1. Peer reviewed

    Investgating resistivity - Planning and Implementing

    4 star(s)

    which doubles this error, increasing it further to 4%, a very significant amount. To keep this error to a minimum, the thickest wire possible was used, while still being thin enough to be easily straightened and kept taut.

  2. Finding the Resistivity of a Wire

    Current (Amperes, ±0.01) Voltage (Volts, ±0.01) Repeat 1 Repeat 2 Repeat 3 Repeat 1 Repeat 2 Repeat 3 1.000 0.50 0.51 0.50 0.88 0.90 0.88 0.900 0.50 0.50 0.50 0.79 0.80 0.79 0.800 0.50 0.50 0.50 0.71 0.71 0.71 0.700 0.50 0.50 0.50 0.63 0.63 0.62 0.600 0.50 0.50 0.50

  1. Physics - Resistivity

    As we can see if I was to work out the resistance of a particular wire I would need to take into account the length, temperature, area and material of the wire. The relevant property of the material is its resistivity.

  2. Choosing a light source

    I investigated the red and the orange bulbs first. Lesson 2: I started to continue with my experiment/s, but this time I was investigating the green and the royal blue light bulbs. Lesson 3: I finished off doing my last experiment, investigating my last light bulb source, which was (the white)

  1. Characteristics of Ohmic and Non Ohmic Conductors.

    Plastic is an example of a covalent substance. In circuits an ammeter is used to measure the current, which is measured in amps, and it is connected in series always. Amps is a measure of the amount of current flowing through the circuit.

  2. Measuring The Resistivity Of A Pencil Lead.

    From these results I can see that the temperature did not rise and thus affect the results. This tells me that my settings for my investigation should be : 1. Power pack set at 4V 2. Current at 0.1A Method Now I have completed the preliminary work I am able to start my main investigation.

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