The question is:

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The answer is:

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My question is how did he get the 100 (highlighted)?


PPI PE Power Reference Manual, 4th Edition – Comprehensive Reference Manual for the Closed-Book NCEES PE Exam

Publisher : PPI, A Kaplan Company; Fourth edition (January 31, 2021)

ISBN-10 : 1591267838

ISBN-13 : 978-1591267836

by John A. Camara PE

  • \$\begingroup\$ Isn’t there a frequency provided somewhere? \$\endgroup\$ May 13, 2021 at 12:55
  • \$\begingroup\$ Or simply ignore the slight error in assumptions \$\endgroup\$ May 13, 2021 at 13:19

1 Answer 1


That 100 pops up for the omega. With small approximation I would say that you have a 16.7 Hz system :) one of my favorite ;), the supply of a Swiss, German, Austrian, Swedish railway. 2 * pi * 16.6667 Hz = 104.7 rad/s. (thanks @user2233709)

Otherwise it is just a good round number without physical explanation (I do not think it is easy to find a system with 15.915 Hz of fundamental).

Note: that 100 confirmed by the "100 rad/s" used one line below.

  • 1
    \$\begingroup\$ Looks plausible +1 for analysis \$\endgroup\$ May 13, 2021 at 13:20

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