investigating the relationship between the diameter and the current in a wire at its melting point
Investigation Report
Aim
Theory
Electrical resistance is a measure of the degree to which an object opposes the passage of an . The unit of electrical resistance is the . Its quantity is measured in .
Resistance is the property of any object or substance of resisting or opposing the flow of an electrical current. The quantity of resistance in an electric circuit determines the amount of current flowing in the circuit for any given voltage applied to the circuit.
Some formulae for resistance are
where
R is the resistance of the object / Ω
V is the potential difference across the object / V
I is the current passing through the object / A
(Ref. http://en.wikipedia.org/wiki/Electrical_resistance)
where
R is the resistance/ Ω
ρ is the resistivity / Ωm
l is the length of the wire / m
A is the cross section area of the wire / m
A = π()
= π
where
A is area / m
d is the diameter / m
Putting the formulae together, so
(Ref. http://physics.bu.edu/~duffy/PY106/Resistance.html)
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Peer Reviews
Here's what a star student thought of this essay
Quality of writing
The layout is good with good spelling, punctuation and grammar in general. The appropriate scientific terms are spelt correctly. Overall, a good report with some room for improvement.
Level of analysis
The physical concepts aren't discussed in particular detail but it is largely accurate, with some relevant physics discussed.
Response to question
This is a good report but a lack of conclusion and some significant errors in analysis of uncertainties have let it down somewhat. The writer initially makes clear what the task is and how they approach it. The explanation of the equations are good but the full derivation and rearrangement isn't required in this type of report. For a final report, the full results before averages are taken should be relegated to an appendix. The biggest problem is that the results are actually OK and the final graph reasonable. The actual uncertainty is approximately 10% rather than the 100% quoted. This can be determined from your graphing software, which usually has a value for this.
