<P> For one of the K Project tests, Soviet scientists instrumented a 570 - kilometer (350 mi) section of telephone line in the area that they expected to be affected by the pulse . The monitored telephone line was divided into sub-lines of 40 to 80 kilometres (25 to 50 mi) in length, separated by repeaters . Each sub-line was protected by fuses and by gas - filled overvoltage protectors . The EMP from the 22 October (K - 3) nuclear test (also known as Test 184) blew all of the fuses and fired all of the overvoltage protectors in all of the sub-lines . </P> <P> Published reports, including a 1998 IEEE article, have stated that there were significant problems with ceramic insulators on overhead electrical power lines during the tests . A 2010 technical report written for Oak Ridge National Laboratory stated that "Power line insulators were damaged, resulting in a short circuit on the line and some lines detaching from the poles and falling to the ground ." </P> <P> Nuclear EMP is a complex multi-pulse, usually described in terms of three components, as defined by the International Electrotechnical Commission (IEC). </P> <P> The three components of nuclear EMP, as defined by the IEC, are called "E1", "E2" and "E3". </P>

What is the effective range of an emp weapon