# kirchoffs law

Discussion in 'Electronic Basics' started by Sunil, Jan 2, 2007.

1. ### SunilGuest

hello...my name is sunil. I am currently doing my first year
Electronics and communication engineering in chennai. We had electric
circuits lab the other day and our prof told us that we had to perform
an experiment to verify kirchoff's theorems (both of them). Though i
know the theory, i am unable to imagine an experiment. The prof also
told us that we had to do this experiment on a breadboard. Can someone
help me??

2. ### Mikkel LundGuest

Sunil skrev:
Then you don't know it ;-) Imagine a voltage reference and a number of
resistors in series.
If no, see:
http://phoenix.phys.clemson.edu/labs/223/ohmslaw/index.html

3. ### John PopelishGuest

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
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.

4. ### PeteSGuest

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

5. ### PeteSGuest

Posted to a.b.s.e

Thanks,
Rich

7. ### Charles SchulerGuest

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!

8. ### PeteSGuest

Hey - I tried

Cheers

PeteS