given this circuit...

how could one reason that KVL applies to this (green) loop?

Is it just zero? There is no current flowing between a and c?

 

edit-- nevermind.... Im interested to find out what the answer is now.

 

peterpants,

Is it just zero? There is no charge flowing (don't say "current flowing") between a and c?

There is no charge flowing through a and c because it is shorted. No voltage either.

how could one reason that KVL applies to this (green) loop?

No voltage sources in the green loop, no voltage used in any of the circuit elements. KVL is 0 = 0

Ratch

 

if short circuited from A and C there is no current flowing. There can be Voltage, but no current .

 

There cannot be voltage across a (ideal) short. Voltage implies current.

The only voltage drop in this circuit will be across the 3 ohm resistor.

 

Basically, don't try this circuit at home