Re: How would you create a controlable electric force?

Hi David,
The question you have asked is a bit tricky :) , since you need a 
generator (as you have mentioned) which generates electricity in spurts 
("jolt of electricity", as described by you).
The coil and magnet experiment, is the basis of creating the mordern day 
generator. This produces electricity in a continuous manner. The principle 
of such generators is based on the fact that whenever a magnetic field is 
moved across a coil, the magnetic lines of force (or flux lines) are cut 
by the coil and electricity is generated as a result. 
 
The voltage generated by the experiment depends on the number of 
conductors (wires) present. Hence the more the number of conductors, the 
higher the voltage. The voltage produced also depends on the number of 
magnetic poles ( Note: Each magnet has 2 poles), the speed at which the 
magnets (or wires) rotate and the strength of the magnets. 
Rotating a simple generator (like the one you are referring to ) would not 
be able to produce a sufficient charge to give you a shock!
There could be many methods employed to generate a high charge:
 
1) Adding a number of capacitors at the end of the generator wires would 
help store some of the excess charge. This excess charge can then be used 
to give a jolt (shock).
 
2) A simpler solution would be by using a piezoelectric material. This 
material generates voltage when subjected to mechanical stress ( when 
compressed). This is the basic principle of operation of household gas 
lighters (starters). The material can generate sufficient amount of 
electricity and by holding the two ends a high amount of shock may be 
experienced (DO NOT DO THIS AT HOME). 
 
As for your further question regarding discharging of the generator, the 
generator would lose all its charge once the rotation of the magnet 
ceases. The generator does not store any charge. So irrespective of 
whether you use the charge generated or not, you lose all the charge once 
the generator stops working.
 
Hope this helps. Ill be glad to answer any doubts that I may have still 
not cleared.
 
Nauzad