Sources of Error in Our Implementation

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Sources of Error in Our Implementation

Systematic errors

> The temperatures on the mercury thermometer may be inexact e.g. may

be out by one degree centigrade.

> It has been assumed the volume of gas is contained in a compete

cylinder when in fact this is not necessarily true, due to:

o Spherical shape of the sulphuric bead above it

o Residue in the tube

o Changes of diameter within cylinder

> The volume of air is being partly compresses by the weight of the

sulphuric acid bead above it. Therefore the volume may not

increase/decrease in proportion to how it would do naturally

Random Errors

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> Eye reading of temperature readings are likely to cause a certain

amount of inaccuracies.

> The curve of the liquid bubble could lead to readings taken from

different parts of the bubble making the results inaccurate.

Most Significant Error

The most significant systematic error is the measuring of the

temperature of gas inside the capillary bubble. Because it is not

realistically possible to measure the gas bubble directly ,the water

bath surrounding it is measured on the assumption that they are both

the same temperature. This may be inaccurate because:

- Air inside the capillary of the bubble has a different specific heat

capacity than the water in the beaker; therefore even with the same

amount of energy applied to both substances they will emit different

amounts of heat

- Air bubble is insulated by the glass capillary, therefore it is

likely the gas bubble may be at a lower temperature than the

thermometers suggests

Error estimation

The Reading of the height of the bubble c...

... middle of paper ...

...his is because the

equipment used is not complex and there are few things to go wrong.

This reduces the likeliness of their being anomalous results.

Looking at the table, there is an anomaly of results between the 90

and 100 degree readings of the second repetition. Despite a rise of

ten degrees centigrade, there is difference in the height of the

bubble when heated between. This is surprising because in all the

other results as more heat is added the height of the bubble

increases.

This can be explained by the nature of liquid mercury in the

thermometer. Like all liquids it is cohesive making it stick to the

sides of surfaces. Therefore the mercury may not expand smoothly, but

in spurts where the expanding force exceeds the cohesive force of

sticking to the sides resulting in false measurements of temperature.

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