Resistance & Resistivity, Example Problems

Includes four different worked examples for calculating resistance and resistivity.

Resistivity is a property of a material that tells you how strongly it resists or conducts the flow of electric current. A low resistivity indicates a material that allows the flow of electric current. Resistivity is commonly represented by the Greek letter ρ (rho). The SI unit of electrical resistivity is the ohm-meter (Ω⋅m). Resistance of a conductor is directly proportional to the length of the conductor and inversely proportional to the cross-sectional area of the conductor.

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[Samuel-jvhu]

Show us the process of calculation too, don't skip it

[Savage-lxyj]

Excellent! Busy on Sunday morning! Once again, the practical application is really helpful! Thanks again, great video!

[rochelletimosa]

Why there's no step by step computation for R, my calculator didn't get the answer

[animeaddicted]

Thanks sooo much I finally understand it!! You're an amazing teacher!

[JaykeSapalaran-iqqs]

Great video tutorial ❤ thank you for sharing your knowledge and experience 🇵🇭🫡

[arwamohamed]

how to get resistance if i have a hollow copper tube length 5m and has external diameter10cm and its walls are thick 5mm the resistivity is 1.7×10power-8

[freedomalozie]

Good day sir. Pls, how can I measure or calculate the resistance per unit length of a constantan wire.
You can also refer me to any experiment you have done. Thank you.

[jelynugdiman]

Wow! Its very clear for me now. Thank you for this video.

[luhanasachi]

Thanks very much now am more than ready for the exam tomorrow ❤❤💪💪

[ThePropozi]

Hello, first I must praise ... a brilliant lecture. Can I have an explanation, please?
R = 2.65x10-8 x 10 / (pi) 3.14 (1.5x10-3) 2 = 3, 75x10-2ohms
in my calculation it comes out:
R = 2.65x10-8 x 10/4.71x10-6 = 5.62x10-2ohms
Where am I making a mistake?
Thank You
Kind Regards

[gooshawn]

In my book, the resistivity of aluminum is 2.75x10^-8 ohms•m

[increasejornsen]

This comment was really helpful but how do I do the maths that"s kinda like my problem the indices stuff( how do we divide the raise to power minus stuff)😊😅

[betsonChibuye]

Am trying Puch on my calculator but the figure you are giving out is not working

[vhvspzt]

Good Day Sir, Why the value of you copper resistivity is 1.68x10^-8? I thought its value was 1.72x10^-8 Ohm-m.

[bratyamon]

Want more problems including circuit diagrams from this chapter....nice vid sir 😎

[vusumuzimsibi-mzkn]

On example number 3 did reciprocate to get that P=R•A/L like how did you get there?

[sarfraj_]

It's very helpful for me, thanks for uploading these amazing videos

[mohammed.a]

in problem number 3 where did u get the 10 from

[khadarmoxmed.]

R = P×L÷A
What 'P' stand for in the formula please?
And where it's come from?
I studied few days ago but I didn't understand it, please help to explain me.

[FSISThakurAshish]

Calculate the resistance of 915 meters length of a wire having a uniform cross-sectional area of 0.77 cm² if the wire is made of copper having a resistivity of 1.7 × 10^¯6 ohm cm.