Measure the resistance of a coil of wire using a voltmeter/ammeter

[PakiPie]

hey everyone.

physics doesn't make sense to me. i need help (!) esp. since I am considering choosing it on highlevel in the IB Diploma programme I am in right now.

anyway. so i have to answer this question for the class on wednesday, but I am totally lost. i would appreciate it a lot if someone could help me ASAP!

k, I am supposed to describe with the aid of a circuit diagram how i would measure the resistance of a coil of wire using a voltmeter/ammeter method. what additional measurements would be necessary in order to determine the resistivity of the material of the coil? i am also supposed to state the required formula of course.

THANKS!

 

[Galileo]

Hi PakiPie.

Just use Ohm's law: $V=IR$

So if you know the potential difference V over the coil and the current I flowing through it, you can find the resistance. Its simply $R=V/I$.

I'd also add some other known resistance in the circuit as to avoid a shortcircuit. The resistance of the wire alone is probably very low.

 

[wais]

First of all, don't worry, physics can be challenging but with practice and patience, you can definitely excel in it! Now, let's get to the question.

To measure the resistance of a coil of wire using a voltmeter/ammeter, you will need to set up a simple circuit. Connect the coil of wire in series with the ammeter and a power supply, and in parallel with the voltmeter. Make sure the power supply is providing a constant and known voltage.

Next, turn on the power supply and take note of the current reading on the ammeter and the voltage reading on the voltmeter. The resistance of the coil can be calculated using Ohm's Law, which states that resistance = voltage/current (R=V/I).

To determine the resistivity of the material of the coil, you will need to measure the length and cross-sectional area of the coil. This can be done using a ruler and a caliper. The resistivity can then be calculated using the formula resistivity = (R x A)/L, where R is the resistance of the coil, A is the cross-sectional area, and L is the length of the coil.

In summary, the required formula for measuring resistance using a voltmeter/ammeter method is R=V/I, and the additional measurements needed to determine the resistivity are length and cross-sectional area. I hope this helps and good luck with your physics studies!