Question

In the event that the Wheatstone Bridge is NOT level (balanced), can the Series circuit be resolved? Can it be solved in parallel? What method would you use?

Answer 1

No, we cannot use series / parallel equations in an unbalanced Wheatstone bridge.

Here is an example of unbalance Wheatstone bridge

Now, read carefully. I am going to tell you you a trick to solve this bridge

R ( total) = four terms / two terms

means in numerator , we will have four terms and in denominator , we will have two terms.

first, let's solve numerator.

first multiply all resistors in crossed way ( 1 * 5 * 4 = 20) and ( 2 * 5 * 3 = 30 ) - we got two terms.

Now,

multiply the resistors on left two branches and then multiply with the sum of other three resistors.

means 1 * 3 * ( 5 + 2 + 4) = 3 * 11 = 33  

same thing for right

2 * 4 * ( 1 + 3+ 5) = 72

now, we will find two terms for denominator.

for first term, Add left resistors and middle resistor, we go 1 + 3 +5 = 9

same for right, 5 + 2 + 4 = 11

multiply these two 9 * 11 = 99

now for second term, just take square of middle resistor, 52 = 25

now

R (total) = 20 + 30 + 33 + 72 / 99 - 25

R (total) = 155 / 74 ohms