JanusBac

Kirchhoff's circuit laws

The laws of Kirchhoff's circuits include two equations that deal with the difference potentials and currents in electrical circuits.

• The Kirchhoff's first law, Kirchhoff's states that, for any node in an electrical circuit, the sum of currents flowing into that node is equal to the sum of currents flowing out of that node.
• The Kirchhoff's second law say that the sum of the potential differences around any closed loop is zero.

There are many sources on the Internet where you can find detailed considerations on this subject - e.g. look here.

These are fundamental laws in electricity and everyone should know them. These laws can be very easily tested experimentally. You need a few resistors, a voltmeter and an ammeter, and a power supply. So, practically all school laboratories are equipped with the appropriate equipment to do such experiments.

However, you may not be able to go to school because of a pandemic or laziness. So I have prepared a home lab for you - click here.

In my lab, you have a ready electrical circuit with three resistors and the rest of the equipment. As I hope you know the resistor has electrical resistance. Different resistors may have different resistances. Everyone who enters my lab gets the same three resistors. If you want to use other resistors for your experiment, you must download them from stock. To download another set of resistors, you must have the code for the propere shelf in my stock. I give out the codes during my classes. If you are not my student, you can use the universal code available to everyone (101100100).

What experiment can be done?

• Set the output voltage of the power supply.
• Measure voltages and electrical currents for all resistors.
• Use Kirchhoff's law and calculate the resistance of each resistor.

Good luck :)