Subject: When high current flows through, the connector see

It seems a common phenomena if you often play with sparks that whenever a spark
occurs between two conducting material, the two material seems to have a force
which hold them together when you pull them apart during the spark. Spark
usually occurs whenever there is a high potential difference between two
material (I play that using back emf of a coil) but I recently play with 2-4mF
capacitors charged to around 12V and I notice that spark is produced even with
such low voltage. I discharge the capacitor in a short circuit and at the
instant when I short circuit by putting two wire together (spark may accompany),
there is a significant force preventing me from pulling it apart.
I wonder what causes that force? if it is under high voltage, it can be due to
electrostatic force but it is ruled out as it is only 12V. I am thinking it has
something to do with breaking a high current circuit but do not know what it is.
Don't worry about me playing with sparks, I do that only using dry cells.

Re: When high current flows through, the connector see