kirchoffs law

Sunil skrev:

Then you don't know it ;-) Imagine a voltage reference and a number of resistors in series. If no, see:

Kirchoff's voltage law says that the sum of all voltages around a loop must add up to zero. Connect some resistors in series around a loop that includes a voltage source (a 9 volt battery, perhaps), measure the voltage across each resistor and the source, keeping careful track of the polarity relative to the direction you go around the loop, and add them up and see how close to zero they total.

Kirchoff's current law says that the sum of all currents entering a single node add up to zero. So you arrange for some currents to arrive at a single node, measure all of those currents by inserting a current meter in series with each, using the same polarity for all (say, positive meter lead toward the node in question) and add the currents up and see how close to zero the total is.

Both these experiments may show a small non zero total, because of measurement tolerances and the the fact that you have not corrected for the way the measurements change the situation. But the results should be pretty close to zero. Your analysis of the experiment should delve into these effects.

If the OP can access a.b.s.e I might put a schematic of a test circuit; it's up to the OP to do the measurement, of course.

Having taught, I understand the gap between what one hears from a lecturer and actually constructing something to test it - besides, it's s.e.b and New Year to boot :)

Cheers

PeteS

Posted to a.b.s.e

Nah - googlegroups.

Thanks, Rich

Kirchhoff's voltage law ... a series circuit should do it (measure all the voltage rises and drops and they should sum to zero).

Kirchhoff's current law ... a parallel circuit should do it (measure all the node currents and they should sum to zero).

Or, get fancy and use an unbalanced bridge circuit to demonstrate both laws (lots of loops and nodes to play with). Your Prof will be impressed!

Hey - I tried :)

Cheers

PeteS