Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
(10^(56/20) microvolt/meter)^2 / 377 ohm * 4 * pi * (3meter)^2
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random