What Are Common Sources of Error in an Electric Field Mapping Lab?

[mich_v87]

hey...we've done few days ago a physics lab experiment about the equipotential lines and electric field where we used the following apparatus:
a 6-volts battery , contact switch, wooden board with spring contacts, hand probe, fixed probe,galvanometer,resistance box,wires and conducting papers

I just like to know what can be the possible error sources concerning this experiment...as for me i found the following errors:

The first possible error is the unspecific reading on the galvanometer
Second, the probe is circular so we can't specify the reached point exactly since it's head is not pointed...
The third error found is that the conducting paper isn't uniform...so the electric field isn't conserved

I'd like to know if what i wrote is write and please suggest some more possible errors that can be made in such an experiment

thank u

 

[quantumdude]

Sorry for the late reply. In case you're still interested, here are my comments.

When looking for sources of error in an experiment, one good thing to do is to look for simplifying assumptions in your theory. Your theoretical model most likely assumes the following:

1.) You are using an ideal galvanometer.
2.) Your wires and circuit elements have zero resistance (except for resistors of course).

In addition to that you can get errors by using nominal values of circuit element ratings, instead of measuring the ratings. For instance, in your theoretical calculations did you use "6 V" as your source voltage? Or did you take a voltmeter and actually measure the potential difference across the terminals? If you did the former, then you probably picked up some error from that.