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    Working with Electrical Grounding and Polarity

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    To whom it may concern,

    From chemistry I understand that electron flow is from negative to positive, in the external circuit.
    I also understand that "conventional current" flows positive to negative, and is used to solve mathamatical electricity problems and it was determined back in the day as current direction. But, if the actual physical flow of current is from neg to pos why do we ground the negative terminal of DC circuits. Wouldn't the electrons go straight into the ground and not return to the positive terminal to complete the circuit. In a car for example the neg terminal is grounded. If DC flows in one direction how can it go from the positive terminal to ground/neg?

    Thank you in advance

    Matt

    © BrainMass Inc. brainmass.com September 26, 2022, 10:35 pm ad1c9bdddf
    https://brainmass.com/engineering/electronic-engineering/working-electrical-grounding-polarity-34085

    SOLUTION This solution is FREE courtesy of BrainMass!

    A ground is defined as a low-impedance electrical connection to earth. Also a common reference point in electronic circuits. We know that electrons flow from negative to positive but we are taking the direction of current from postive to negative. Ok

    For the flow of electrons an electric field is required (to exert force on them to move). If we connect the negative terminal to ground, no elecron flow can occur as there is no potential difference between the ground and the negative terminal.

    In most electrical appliances, a positive shift of the voltage level is considered a signal (or noise); So if we properly ground the negative terminal, noise reduction is high.

    Once you ground a terminal, its potential is assumed to be zero and electrons can flow from this point to a +ve terminal as there is a potential difference.

    Also, without connecting one terminal to ground, we cannot expect a "proper ground" from ground. In a car, grounding one terminal to chasis has an added advantage as only one wire is required to power the bulb (the other terminal is chasis itself)

    A ground is simply an object which serves as a seemingly infinite reservoir of electrons; the ground is capable of transferring electrons to or receiving electrons from a charged object in order to neutralize that object.

    1)If the object to be grounded is negatively charged, grounding lets excess electrons to flow from the object into the earth or other large substance, or

    (2) If the object is positively charged, electrons flow from the earth or other large neutral substance into the object.

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    © BrainMass Inc. brainmass.com September 26, 2022, 10:35 pm ad1c9bdddf>
    https://brainmass.com/engineering/electronic-engineering/working-electrical-grounding-polarity-34085

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