I wanted to see if some of my students could work out the inductance of a coil i wound around an iron core using any of the equipment they wanted in the lab. Before that I had shown them the non-ideal nature of the coil by connecting it in series with a DC ammeter and battery and the ammeter showed a few amps.

Kate gave it a go by selecting a variable capacitor with accurate scale of 100-300 microFarad. She connected this in series with the coil to a 12V/50Hz AC supply. She monitored the voltage across the coil and the capacitor, carefully adjusting the latter until the two voltages are exactly the same. The capacitance read 219 microFarad. Using the equation
f = 1/2pi(LC)*1/2

she got a value of 46.3 mH for the inductance

Sharon did something different. She chose a 6.00 ohm resistor and connects it in series with an AC ammeter and the 12V/50Hz AC supply. She records a current of 0.657 A and the voltage across the resistor is 3.94 V and across the coil it is 9.53 V

Have you any idea how she used this figures to get the correct inductance of the coil?
Have a go and let me know.

Be critical of Kate's expreriment


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whoaaaa, physics is really hard to learn >.>

I don't understand a thing naa~ I'm bad at physics XDD
But nice post, Kiwiman-san :)

Thank you

Thank you for you'r comment, You'r English is good aswell ^w^

Re: Thank you

> Thank you for you'r comment, You'r English is good aswell ^w^
Of course- it is my first language- I only know a little Norsk cos I lived there for one year
ver so god!

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Oh sorry, my bad >w<;; That's cool! I'm from Finland but moved to sweden when I was 3 so I can speak both of the languages :) (And then I have English classes)


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