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

Investigate the relationship between temperature and resistance in a thermistor.

Extracts from this document...

Introduction

Thermistors Investigation
Aim

To investigate the relationship between temperature and resistance in a thermistor.

Introduction

A current is the flow of charge round a circuit, this can be in the form of ions in a liquid or electrons in a metal.

Resistance is anything that slows the flow of electrons round the circuit.

Ohm's law states that the voltage is equal to the current multiplied by the resistance - V=IR

This can be re-arranged to say R=V/I.

Ohms law states that in a metal component the ratio of voltage to current remain constant, meaning that the resistance stays the same as long as the temperature remains the same. In this experiment I will be changing the temperature therefore this rule will not apply, however the equation R=V/I is always true as it is the way resistance is defined.

In a wire when the temperature is increased the resistance increases. This is because at a higher temperature the lattice atoms are vibrating faster and are colliding with the electrical current and slowing down the flow of charge.

This is also true in a thermistor but there is another competing effect because it is a semiconductor. Being a semiconductor means that the outer electrons are not free at room temperature but when heated the get more energy and are freed. This means that there are more electrons available to conduct.

...read more.

Middle

image02.png


Experiment Diagram


Results

Temperature (0C)

Current (A)

Voltage (V)

Resistance (Ohms)

Average Resistance (Ohms)

Trial 1

Trial 2

Trial 3

Trial 1

Trial 2

...read more.

Conclusion

0C and see if the resistance would start to increase again after the thermistors atoms have lost all their outer electrons and the lattice atoms continue to move faster slowing down the flow of current. I could not use water to do this as water can not be heated beyond 1000C, I would have to use a liquid with a higher boiling point such as oil. For this experiment I would set up the equipment in the same way but use oil instead of water and continue beyond 1000C. I could also investigate whether the length of a wire had an effect on the resistance of the circuit there would be more lattice atoms and may be a higher resistance.

I would also like to try lower temperatures to see if there was a minimum energy needed to free the electrons if so the graph would be-

image05.png

...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. Investigate how the temperature affects the resistance of a thermistor.

    The type of flame I use to heat my water/oil bath must also stay constant because different types of flames give off more heat for example a roaring blue flame gives off a lot more heat than a large yellow flame (the safety flame)

  2. Experiments with a thermistor

    * For each temperature, the voltage reading on the multi-meter slightly fluctuated, therefore I had to repeat the experiment twice and calculate the average to minimise the percentage error of the values. EXPERIMENT #2 Investigation For the second experiment, I performed a similar kind of experiment, but from a different sort of perspective.

  1. Effect of changing the temperature on the resistance of a thermistor

    Voltmeter(V) 35? 0.0Slop014 1.4 35? 0.0017 1.6 40? 0.0015 1.3 40? 0.0018 1.6 45? 0.0017 1.2 45? 0.002 1.6 50? 0.0018 50? 0.0022 1.2 55? 0.0021 1.2 55? 0.0024 1.2 60? 0.0022 1 60? 0.00245 1.1 65? 0.0023 1 65? 0.0026 1 70? 0.0025 0.95 70? 0.0028 1 75? 0.0025 0.9 75? 0.003 0.9 80? 0.0028 0.8 80?

  2. I am going to investigate what the resistivity is of a pencil lead. ...

    However, the temperature of the room may have varied from the start of the experiment to the end which would have meant the temperature of the pencil lead did not remain constant along with the fact that I may not have left the pencil lead long enough to cool could have caused a slight error in the reading.

  1. Investigating the effect of 'length' on the resistance of a wire

    ensure that results are more accurate and that no short-circuiting will occur. All of the variables above must be kept the same as they all will affect the resistance of the wire. Independent variable * The length of the wire, I will do this by changing the length of the wire using the crocodile clips.

  2. Investigating Ohms law

    2.00 146.4 2.00 146.6 2.20 154.1 2.20 153.7 2.20 153.6 2.20 153.8 2.40 160.7 2.40 160.8 2.40 160.8 2.40 160.8 2.60 167.5 2.60 167.3 2.60 167.4 2.60 167.4 2.80 174.0 2.80 173.8 2.80 173.7 2.80 173.8 3.00 180.0 3.00 180.2 3.00 180.0 3.00 180.0 3.20 186.1 3.20 186.0 3.20 186.1

  1. Investigation into how the resistance of a thermistor varies with temperature.

    Revision book page 60, and in a physics textbook called Complete Physics by Stephen Pople. Both books state that the way to calculate the resistance is to use the following formula triangle and substitute in my specific calculations: Thermistor In the Letts' "Double Award Science Physics Higher" GCSE Revision guide

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

    = 0.895 m2= ( 5.5 - 3.55) / (8.0 - 4.88) = 0.625 ?m = [(0.895 - 0.727) + (0.625 - 0.727)] /2 = 0.033 The value of coefficient of static friction �s: 0.727 � 0.033 The maximum error in the value of coefficient of static friction �s: 0.727 � 0.033 Maximum percentage error in the value

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