and the input, output, and load impedance all determine what 'flavor' you want.
If you are feeding a high impedance load from a lower impedance source, voltage gain is generally what you want.
Low impedance loads often rely more on current gain in the preceding stage
to ensure adequate signal...
Change in e sub r.
This changes the ratio between B field and E field intensity in the location.
tangential current exists to carry this E field component.