Shorebrook PE Power Exam Question 77 - is this is a thumper (device used to locate faults)?

Hey guys,

On Shorebrook PE Power Exam question 77, is this circuit a typical thumper (the device used to locate faults)? I haven't seen this circuit before in other PE exam prep materials, and the only other reference to a thumper is in one of the Cram for PE Power exam questions.

From what I understand, the left side of this circuit is basically a Wheatstone Bridge (balanced, since the measured current in the middle (A) is zero). On the right side of this circuit, it seems that:

Distance to fault = Total cable length / One-way cable resistance = Total cable length / (Round trip cable resistance / 2)

Thanks for any input or clarity on this! I haven't seen this in any other PE exam prep material so far...

https://en.wikipedia.org/wiki/Murray_loop_bridge

Chattaneer PE said:

https://en.wikipedia.org/wiki/Murray_loop_bridge

Click to expand...

That sheds some light. Thank you for your responses in this and my other topic questions!