Solving Circuit Problems Literature Review Example Nz
Consider for example the following question about the circuit below: My first question is, if there are any resources where the qualitative reasoning of experts in solving problems like this, is documented in detail.
My second question is, how you as an expert would proceed in detail to solve the example problem above.
Let’s use this circuit to illustrate the method: , respectively.
Bear in mind that these directions of current are speculative at this point.
In some cases we may discover that current will be forced back through a battery, causing this very effect.
The important thing to remember here is to base all your resistor polarities and subsequent calculations on the directions of current(s) initially assumed.
It isn't, because that would only be true if L2 was shorted. I've never seen a resource where this reasoning is explained.
Logical thinking seems to be the key, maybe a course in logic (formal systems) would help.
Suppose the power supply is 12V and each of the resistors is 2$\Omega$. Power in L1 is now (4A)$^2$ $\times$ 2$\Omega$ = 32W, and the power in L2 and L3 (2A)$^2$ $\times$ 2$\Omega$ = 8W.
The polarity is positive where the current enters the resistor and negative where it exits the resistor: The battery polarities, of course, remain as they were according to their symbology (short end negative, long end positive).
It is OK if the polarity of a resistor’s voltage drop doesn’t match with the polarity of the nearest battery, so long as the resistor voltage polarity is correctly based on the assumed direction of current through it.
However, we do know that all three voltages must algebraically add to zero, so the equation is true.
We can go a step further and express the unknown voltages as the product of the corresponding unknown currents (I) and their respective resistors, following Ohm’s Law (E=IR), as well as eliminate the 0 terms: Since we know what the values of all the resistors are in ohms, we can just substitute those figures into the equation to simplify things a bit: ).