Warning (2): get_headers(): https:// wrapper is disabled in the server configuration by allow_url_fopen=0 [APP/Controller/TermsController.php, line 315]
Warning (2): get_headers() [<a href='http://php.net/function.get-headers'>function.get-headers</a>]: This function may only be used against URLs [APP/Controller/TermsController.php, line 315]

reactance, \(X\)

https://doi.org/10.1351/goldbook.R05162
Imaginary part of the impedance.
Source:
Green Book, 2nd ed., p. 15 (https://dev.goldbook.iupac.org/files/pdf/green_book_2ed.pdf)