Series-Parallel Circuits - Technical MCQs

Q1:

Which circuit fault do the meter readings in the given figure indicate?

A The 1 komega.gif resistor is shorted.

B The 4.7 komega.gif resistor is shorted.

C The 2.2 komega.gif resistor is shorted.

D The 3.3 komega.gif resistor is shorted.

ANS:D - The 3.3 komega.gif resistor is shorted.

If 1k is shorted, the current would just flow through it and to the remaining resistors, thus a voltage drop would have occurred.

If 4.7k is shorted, there would still be reading since there would still be a voltage drop in the 2.2k, the same concept applies if 2.2k is shorted there would have been reading since there would be a voltage drop in the 4.7k resistor.

If 3.3k is shorted, the current entering the node from the 1k resistor would go to the shorted circuit and there would be no drop across 4.7k and 2.2k since it has a higher resistance and is connected in parallel with the 3.3k. (Always remember that the current always find the path of least resistance).