On This Page
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IntroductionIntroduction
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AimAim
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ToolsTools
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Steps & MethodsSteps & Methods
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Parameters, Theory & Final LawParameters, Theory & Final Law
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Medical ApplicationMedical Application
Introduction to the Variation of the Resistance with Temperature
The temperature coefficient of resistance is a parameter that describes how the resistance of a material changes with temperature. For metals, the resistance increases approximately linearly as the temperature increases.
Aim Of The Temperature Coefficient Of Resistance Experiment
-Measurement the Variation of the Resistance of a wire with Temperature.
-Measurement of The Temperature Coefficient of Resistance.
Tools Of The Temperature Coefficient Of Resistance Experiment
- Metre (Wheatstone) bridge
- Dry cell
- Resistance box
- Sensitive galvanometer with protective resistance
- Thermometer (0–100 °C, graduated to 0.5 °C)
- Beaker
- Ice
- Test tube containing a coil of wire immersed in paraffin
- Approximately 2 m of iron wire (S.W.G. 34 D.C.C.) for the coil
Steps And Method of The Experiment
Immerse the test tube in a beaker containing finely crushed ice and water.
Leave it for some time until the temperature reaches approximately 0°C.
Connect the metre bridge circuit as shown in the diagram.
When the thermometer indicates approximately 0°C, determine the resistance of the coil using the metre bridge.
Adjust the resistance box to obtain a balance point near the middle of the bridge wire.
Record the temperature and resistance. Replace the ice-water mixture with tap water and determine the resistance again.
Record the temperature immediately after obtaining the balance point. Slowly heat the water bath using a low Bunsen flame.
Measure the resistance of the coil at approximately 10°C intervals, recording the exact temperature for each measurement.
Temperature Coefficient of Resistance Experiment: Theory
Parameters, Graph & Final Law
Table of readings for the variation of the resistance with temperature
Table of the Readings
| θ/°C | L1/cm | L2/cm | Rx/Ω |
|---|---|---|---|
Medical Application
Understanding the variation of the resistance with temperature has direct applications in medical device engineering, particularly where components must maintain stable, predictable performance:
For a diode laser to maintain stable frequency, output power, current, and temperature, its operating parameters must be carefully regulated. A low-cost, low-noise current source can provide the stable current required for laser operation. The current-sense resistor is a critical component and should have high power capacity, low thermal EMF, and minimal temperature dependence. Therefore, a low-cost, high-precision resistor is needed to ensure reliable laser stability.
Frequently Asked Questions About the Variation of the Resistance with Temperature
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