Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 20 replies
  • Subscribers 32 subscribers
  • Views 2048 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Exam question

Eclipse
Guys,

can anyone explain the how the following answer to this  question is derived ( its from an old test paper) which my son is doing, 

The maximum tabulated value of earth fault loop impedance for a circuit is: 1.65 ohms, if the resistance of the line to cpc of a new circuit is 1.13ohms  the maximum accepted external earth fault loop impedance is:

A. 0.52 OHMS

B. 0.45 OHMS

C. 0.35 OHMS

D.0.20 OHMS


The answer given to him is "D"  but no explanation as to how its worked out,

really appreciate any feedback!!
Parents
  • 0
    Which 0.2 can you not see? I have written it out above! There is probably another trick there which is the accuracy of the R1+R2 measurement. Is 1.12 absolute, or is it perhaps 1.13? This question is about test, and test is not a very quick bit of adding up! This might come straight from the old 2391, or perhaps even the new one. The other answers are the result of various common mistakes and misunderstandings.
Reply
  • 0
    Which 0.2 can you not see? I have written it out above! There is probably another trick there which is the accuracy of the R1+R2 measurement. Is 1.12 absolute, or is it perhaps 1.13? This question is about test, and test is not a very quick bit of adding up! This might come straight from the old 2391, or perhaps even the new one. The other answers are the result of various common mistakes and misunderstandings.
Children
No Data

Community Rules & Guidelines