Error source in an experiment

[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.

 

[quicknote]

I would like to commend you for being aware of potential errors in your experiment. It shows that you are thinking critically and taking the necessary precautions to ensure accurate results.

In regards to your identified errors, I would like to offer some suggestions and additional potential errors to consider:

1. Unspecific reading on the galvanometer: This could be due to a faulty or inaccurate galvanometer, or incorrect calibration. It's important to check the calibration of the galvanometer before conducting the experiment and to make sure it is functioning properly.

2. Circular probe: In addition to the issue of not being able to specify the exact point of contact, there could also be errors in the measurement of the electric field strength due to the shape of the probe. It may not be evenly distributing the electric field around the circular contact point.

3. Non-uniform conducting paper: As you mentioned, this can affect the conservation of the electric field. It's important to use a consistent and uniform conducting paper to ensure accurate results.

4. Battery voltage: The 6-volt battery may not be providing a consistent voltage throughout the experiment. It's important to check the battery voltage before and after the experiment to ensure it is stable.

5. Contact switch: The contact switch may not be making a strong and consistent connection, leading to fluctuations in the electric field and inaccurate readings.

6. Human error: This is always a potential source of error in any experiment. Make sure to take your time and be precise when conducting the experiment, and have a colleague double-check your measurements to minimize human error.

Overall, it's important to carefully consider all potential sources of error and take steps to minimize them before conducting the experiment. It's also a good idea to repeat the experiment multiple times to ensure consistent results and to identify any possible errors.