X type capacitors are designed not to fail short circuit and hence cause a massive curent flow and risk of fail. Y type caps are there for personal safety and should not fail and thus cause risk to anyone touching the chassis of some equipment: -



X2 and Y2 are a bit smaller and cheaper than the original X and Y capacitors. Here is a fairly user-friendy site that gives more details.

Difference between Across the Line and Line to Earth
For my calculations, I need increased precision of parameter 'k' in my Manipulate:

Manipulate[
 Plot[Cos[k x], {x, 0, 2 Pi}], {{k, 1}, 0, SetPrecision[4.0, 22], 
  SetPrecision[0.100, 22], Appearance -&gt; "Labeled"}]


However, at the same time, for aesthetic reasons, I want the label to the right of the slider to display only couple of digits.

How this could be done?
