• 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...


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.


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.












































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.  


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)

    the value of I with the internal resistance r and later subtracted it with the value of V in order to obtain the emf (the potential difference of the cell), this formula helped to calculate or to proof the variable of the unknown above symbols especially the emf.

  2. Investigating the E.m.f and Internal Resistance of 2 cells on different circuit Structures.

    External resistor! (value is varied) 2. 3. Process / Method: For this investigation I am going to keep the following factors constant in order to gain an accurate result: * I am going to use the same ammeter and voltmeter for each circuit reading * I will use the

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

    However the suitability of the techniques was doubtful. It was very difficult to get an accurate reading at a precise point because the meters kept flickering between readings.

  2. 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.

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

    2. This case is totally wrong. If the applied force is smaller than the static friction, there will be a net force in the direction f the static friction that is opposite to the direction of the applied force. By the Newton's second law of motion, the block will move in the opposite direction of the applied force.

  2. Free essay

    Finding the internal resistance of a solar cell

    Results Conclusion I have come to the conclusion that the gradient of the line of best fit and subsequently the internal resistance of the solar cell is 5.3 within acceptable limits. I have come to this conclusion because the gradient of the graph that shows that the average or mean

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

    The apparatus that I will need available to me when conducting this investigation is: * A Lemon * A Zinc electrode * A Copper electrode * Voltmeter * Ammeter * Variable resistor * Crocodile clips * Several insulated wires * A sharp knife Method: To complete my investigation I will use the following method: 1.

  2. The potato - a source of EMF

    Maximum Power Theorem: This is the popular theory claimed to have been discovered by Moritz Von Jacobi (1801-1871). The "Jacobi's Law" as it is sometimes called states: "Maximum power is transferred when the internal resistance of the source equals the resistance of the load, when the external resistance can be varied, and the internal resistance is constant."

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