If you touch a power line while in air like a bird, it doesn’t shock you, but if you’re touching the ground, it does. Literally why?
In: Physics
Trace out the path of the current and you’ll see there’s extremely high resistance. When you’re not touching the ground, there isn’t enough current flowing through you to matter because the air provide such high resistance
If you’re on the ground and touch a powerline then the only resistance between the power line and its return path is the 1000-100,000 ohms of resistance that your body provides. For a 10,000V line that means somewhere between 100 mA and 10A will flow through your body resulting in a mix between almost certainly dead, and cooked like a deep fried turkey.
Lets say you’re in a helicopter a few meters in the air when you touch the powerline. The electricity enters your body, then connects to the helicopter, then tries to flow through the meters of air to get to the ground. Your body still has resistance but the meters of air below you provide something between 10^9 and 10^15 ohms of resistance. Now you get a shock of no more than 10 microamps, which is about 1/100 the level that you can feel at all. There is still current flowing through you but not enough to matter.
what flows in the lines is a negative charge, the negative charge wants to get to the positive charge. just like how a battery works, like when you place them in a remote controller you create a bridge from the negative pole to the positive pole, on its way to the positive pole it will power the remote
the ground is also a positive charge, so the negative charge in the power lines will use your body as a bridge to reach the ground. in some cases if the charge is strong enough it can jump through the air to reach the positive pole, which is exactly what the lightning strikes does
electricity doesn’t care about anything it can enter, it wants to reach lower voltage areas (especially the ground). If your body doesn’t offer a path to the ground, the electricity has no where to flow to and so it doesn’t.
Think of flowing electricity like flowing water. If you touch an electric wire but not the ground, you are like a pond connected to a river. Once the pond fills up with water, there is no more flow of water into the pond. If you are touching a wire and the ground, you are more like a channel from the river to the ocean. Water can flow through the channel forever, and never “fill it up”, since it keeps emptying into the ocean. It is this flow of electricity which will kill you. When you are un-grounded, the small amount of electricity that flows into you to “fill you up” does nothing more than cause a minor shock.
Latest Answers