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a generator
Magnetic fields do, because there's no such thing as an isolated magnetic "pole",
and a magnetic line always starts and ends at opposite poles of the same
magnetized object.
But electric fields don't. You can easily have a bundle of isolated positive charge
over here and a bundle of isolated negative charge over there, whereupon the
lines of the electric field start on one bundle and end on the other bundle.
But electric field lines can also exist in closed loops, and they do that in radio waves, where the electromagnetic field propagates with an electric field component and a magnetic field component, and they both form closed loops.
True
an insulator
A short answer:
An electric fence is connected to the ground only when an animal or a human being touches it to complete a circuit from the fence to the ground.
A longer answer:
The wires of an electric fence are not connected directly to the ground because, if that was done, the fence would be shorted out and would not be able to do its job!
This is how an electric fence is actually hooked-up: the electric fence is connected to one side of a specially designed high voltage source and the return side of that source is connected to the ground.
Then, whenever the skin of any animal - or human - touches the wire whilst standing on the ground in bare feet, they get a high-voltage (10,000) DC electric pulse from the electric fence. The shocks are designed to be only enough to make them jump back from the fence, not to "electrocute" them so badly as to cause serious injury or death.
CD
Most great discoveries started out as accidental. The discoverer usually wondered why something happened and began investigating and experimenting to learn about it.
Magnetic fields can be created by charges or the flow of current.
a copper wire carrying current and another magnet.
false
wait for someone from the power company to come ant help - APEX;0
