Understanding the Passive Sign Convention: A Guide for Electrical Engineers

[Eto]

Homework Statement

Please help. I've tried understanding why the values are what they are but I keep getting confused. Can I get a detailed and clear instruction simple enough for a potato to understand.
I understand that both currents are negative because the current to 1 is positive but even then, I need help.

Relevant Equations

I don't know if any equations are involved to make it more understandable

 

[scottdave]

What exactly is your question? Voltage drop implies the voltage has decreased, from a higher value positive to a lower positive. The convention is that current enters into the positive side (higher positive voltage) of a passive device and exits from the negative terminal.

When analyzing an unknow circuit, you often choose a convention (pick a positive terminal and a current direction). Sometimes you get a negative number, which means that you guessed wrong. But not to worry, it just means it is in the opposite direction.

The wording in the problem statement seems a little vague to me, though. They say voltage drop between 1 and 2, but on one of them terminal 1 is positive, the other has terminal 2 positive. To me, that suggests putting the positive lead of a voltmeter on the one labeled (+). Then they say "current entering terminal 1, but then the arrow may be different. My guess is that you hook up an ammeter in such a way that you're expecting a positive number based on the arrow. If you can, try to ask your instructor for clarity as to what you are answering.