a jolt means a kind of a push (not exactly in physical terms always)
(I don't think electricity has anything to do with it)
However it does mean to shock someone but not by means of electricity.
Example -
(Macmillan) This announcement will be a jolt to investors.
(Cambridge) His self-confidence took a sudden jolt with the news that he had not been selected. (Here he did get a shock but not an eletricial one)
Anyway let's try to clarify your doubt here -
Suppose you are having a horrible dream. You dreamt that someone pushed you off of a terrace of 100 storey building and the moment you start to fall down, you are awaken with a jolt. Such kind of dreams always awake you with a jolt. Everyone some or the other times have had experienced these kind of dreams.
If you are riding in a car taking a nap and the car happens to drive along a pothole on the road, then it will jolt you awake.
In your example of the movie 'Inception' the same criteria applies. Except that in the movie the character had to die to be awaken with a jolt.
More examples
- My car just broke down in the middle of the road with a jolt.
- (Cambridge) The train stopped unexpectedly and we were jolted forwards. (means we were severely pushed forward by the jolt)