Simple electricity question. Please check if my answer is the correct one please!?

Question

Before the nozzle of the fuel pump is inserted into the fuel tank of an aircraft, an 'earth wire' is always connected to the metal frame of the plane. Why do you think this is done?

Ok so an earth wire (something that dissipates charge) takes the charge out of the metal (which it could have gained through friction), making the charge of the metal neutral. This therefore prevents a spark from occuring (attraction of positive to negative).

When I had a look at the ans it said it had zero potential difference and thus a spark will not occur. Is my answer acceptable? Where does potential difference come into it?

Thanks in advance. 10 points for best answer.

Answer 1

ur answer is acceptable

Answer 2

Your answer is correct, but misses the point that an airplane needs a starter motor, which is always charged, and has a polarity.  The earth wire is to unload the charge into the ground.  If you listen to planes starting, you can hear the diff. between the planes engines and the starter motor.  The latter is much higher pitched.  (simplified version)

Peace.

P.S. It started the inferno on the US airship the........ forgot.

Answer 3

The fuel which is pumped to the aircraft is an electrical insulator, and so is the pipe that carries it.

When the  fuel is pumped thought the pipe, a static charge is created  due to friction between the fuel and the pipe. The fuel carries this charge to the aircraft.

This charge builds up on the aircraft, causing a potential difference between the aircraft and the Earth. An electrical spark could then pass between the aircraft and Earth, and you would not want that to happen near fuel.

When the aircraft is connected to Earth, any charge that builds up on the aircraft is led away to Earth, and there is zero Potential Difference between the aircraft and Earth.

Note that this only happens when you pump a fuel, like kerosene, which is an insulator. When you pump, e.g. impure water, the water itself would conduct any charge away, and earthing is not required.

Answer 4

Thje potential difference comes as a result of the difference in potential between the earth and the charges generated on the plane. Your answer is still acceptable cos what the wire does is to make th potential difference zero so no soparks can occur.

Answer 5

When a metal is connected to a grounding wire, all of the charge flows to the ground making its potential 0.

This makes it "electrically safe." Similarly, when you open up your computer, you want to ground yourself to make sure you don't short a circuit!