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

internal resistance of a battery planning

Extracts from this document...

Introduction

Physics coursework

Investigation to compare the internal resistance’s of different cells.

My task is to compare the internal resistances of different cells.  I will first make a prediction what I think the relation may be.  Then I will carry out preliminary and final experiments. After this I will then evaluate and analyse all of my results.  

Internal resistance is:

“The resistance within a voltage source, such as an electric cell or generator.” (http://www.answers.com/topic/internal-resistance-electricity)

EMF (electromotive force)

“The energy per unit charge that is converted reversibly from chemical, mechanical, or other forms of energy into electrical energy in a battery or dynamo.” (http://www.answers.com/topic/electromotive-force)

No real devices (batteries, amplifiers, generators) are perfect and so all have an internal resistance.  The resistance is caused because the charge has to flow through the cell.  When it does

...read more.

Middle

I set up the experiment as below.  Then I put different cell in and changed the resistance on the rheostat and recorded the results.  

...read more.

Conclusion

9

3.27

2.01

9

2.46

0.77

1.5

1.6

0.13

1.5

1.59

0.17

1.5

1.58

0.2

1.5

1.57

0.22

1.5

1.56

0.25

1.5

1.54

0.29

1.5

1.5

0.39

1.5

1.47

0.47

1.5

1.43

0.58

1.5

1.38

0.69

1.5

1.07

1.75

1.5

0.46

3.75

When doing my preliminary experiment I discovered that it would be better to use digital voltmeters and ammeters rather than one I used as it would be more accurate to use a digital ammeter and voltmeter.  This ensures there will be no errors when reading the values.   In my real experiment will also take repeats and also I will use more cells.  

The Real Experiment Method

I will set up the experiment as below.  I will implement different cells and change the resistance to get at least 8 readings for each cell.  I will wait for the equipment to cool down between each reading.  I will also use the same equipment throughout to attempt to stop any anomalies occurring.  

Safety

The experiment is very safe and so all I need to do is ensure the batteries do not get hot and that they do not leak as the contain very harmful and corrosive chemicals.  

...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

    Internal Resistance of a cell

    5 star(s)

    During the practical experiments, we were not sure yet about our results whether are true or not but after the research it satisfied us with an idea that the voltage of the each cell is inversely proportional to the currents in this case.

  2. Peer reviewed

    Investgating resistivity - Planning and Implementing

    4 star(s)

    The gradient should represent ?/A. Variables The independent variable in the experiment will be the length of constanton wire in the circuit. This variable will be changed, and the dependent variables of voltage and current will be recorded. The resistance in the rest of the circuit will be altered using

  1. In this experiment, we will measure the e.m.f. and the internal resistance of a ...

    the dry cell used in the experiment are calculated in both mathematical and graphical method: For mathematical method, Two dry cells are used: V/V � 0.10 1.40 1.30 1.10 1.00 0.90 0.80 0.60 0.50 0.20 I/A � 0.01 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 V represents the e.m.f.

  2. The potato - a source of EMF

    4. Whenever the current reached the required value of mA the variable resistor was taken out of the circuit and put into the ohmmeter to read the exact load resistance, this value was then put into a column on the data table.

  1. Measuring the e.m.f. And Internal Resistance of a Cell

    This was 0.03 Volts out from the other, but this difference is negligible. I am happy with the values that I have obtained from this experiment; I found no major discrepancies between the expected results and the experimental evidence. I feel that the results and conclusions are accurate to the

  2. Internal resistance investigation - I will conduct the following investigation with the aim to ...

    give it a slightly lower resistance, and record the new readings shown on the ammeter and voltmeter. 8. Repeat this 10 times (the variation of the resistance each time will depend on the min. and max. resistance of the variable resistor I have available)

  1. The aim of the experiment is to verify the maximum power theorem and investigate ...

    of coefficient of static friction �s: = 0.033 * 100% = 3.3% For kinetic friction: According to the equation fk= �k R, The slope of the graph = value of the coefficient of the static friction. The co-ordinate of centroid : (4.88 , 2.80)

  2. Electrical Energy Questions and Answers

    Common source of DC is a battery 5. The flow of positive charges is known as conventional current, therefore conventionl current is a stream of moving positive charges flowing from the positive terminal to the negative terminal. 6. Negative charges move in the opposite direction , this movement is known as electron current 7.

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