Experiment to determine the resistivity of a metal wire
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- Опубліковано 10 чер 2018
- This video shows the experimental procedure to measure current through, voltage across and diameter of sections of metal wire of known length. Current and voltage are used to determine the resistance.
Try the data analysis yourself, download a free worksheet here: physicshq.wixsite.com/alevelp...
Perfect if you're learning physics at home.
In video 2 ( • Experiment to Determin... ) the data is analysed and used to produce a resistance-length graph. And from that the resistivity of the metal is determined.
Electricity experiments, like this one, are mandatory practicals for many physics specifications. So this is good practice for OCR physics A, AQA A-Level physics, Edexcel A-Level physics, CPAC, PAG, practical endorsement.
Relevant concepts: electrical resistance, metal wire, resistivity, micrometer, and Ohm's law.
U man u really saved my future thanks a lot...much love to you
I’ve never saved someone’s future before! You’re welcome 🙏. Much love to you too - especially given the crazy and challenging times we are living through. All the best for the future!
Thanks man this is really helpful and clear!
helped with my homework for the practical tomorrow. Thanks!
Excellent!
Do you have a list of materials that you have used in this demonstration, if so can you please reply and send it here thanks.
Sure:
1 m metal wire under test
Battery pack
Connecting leads and crocodile clips
Ammeter
Voltmeter
Metre rule
Micrometer
Niceeeee vid💎💎
Thanks 🙏
All the best
What should i do to obtain accurate values for L
I can't think of too much to add to a method to enhance accuracy. I would say eliminate parallax error by taking length readings perpendicularly to the scale of the ruler.
One question, why did you use these current and voltage values? I mean, can these values be generalized to any material?
by the way, nice video =)
The voltage across the circuit can be generalised to other materials. But there’s likely a limit as resistivity values diverge from that of this material.
The current values will be closely tied to the material and dimensions. I selected them by finding the max and min and selecting a suitable range within that.
Is it alright if you can write down the method?
Sure.
1. Measure the diameter of the wire at different points. Use the average diameter d to determine the cross-sectional area A of the wire.
2. For a 20 cm long wire, measure the current I and the potential difference V.
3. Record results in a table.
4. Calculate the resistance R of the wire.
5. Increase the length of the wire in steps of 10 cm and determine the resistance for each length.
6. Plot a graph of resistance R of the wire (y-axis) against its length L (x-axis).
may i ask, is there any procedure for this experiment?
particularly on setting up the materials
what was the voltage that you supplied?
The total emf was approx 6.0 V. But in changing the length of the section of wire the terminal p.d. of the battery of cells changes. I was measuring the p.d. across the section of wire for each length (alongside the current).
Can I do this for steel?
Yes. And for any material you can pass a measurable current through.
Considerations:
Increasing cross sectional area will increase magnitude of current.
A higher sensitivity ammeter may be needed if the material’s resistivity is substantially higher.
Not a great video to be honest, was hoping for some calculations.. not to watch you measure a wire for 7 minutes
Thanks for taking the time to watch and write a comment. This is a video of the experiment, analysis of the results is done in the follow up video: ua-cam.com/video/wiLltRA0lfE/v-deo.html