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Drag the ‘Resistor’ to the gap 2 and 3 of the Carey fosters bridge.
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Drag ‘Fractional resistor' to gap 1.
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Drag the Battery to space in between the two ‘Resistors’.
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Drag the copper strip to gap 4.
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Press the continue button, on the top.
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Click and unmark the resistance which has to be introduced in ‘Resistor’.
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Power On button to start and power off to stop the experiment.
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Change the position of jockey to get balancing length l1’.
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Reverse connection button to interchange copper strip with fractional resistor.
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Move jockey to get balancing length l2’.
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Resistance per cm of bridge wire is found using equation
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Repeat the experiment for different values of Resistance.
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Repeat steps 1-3.
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Drag ‘Unknown resistance 1’ to gap 4 in bridge.
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Introduce the resistance and move jockey to get balancing length l1.
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Reverse button to interchange unknown resistance 1 with Fractional resistor.
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Move jockey to get balancing length l2.
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Unknown resistance value is found using the equation
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Repeat the experiment for different temperature t1, t2….and note corresponding resistance X1, X2...
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Temperature coefficient of resistance is found using equation
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Repeat the experiment for unknown resistance 2.
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A graph is plotted between values of X and t , which gives a straight line, whose slope is α.