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How is the most economical voltage selected for transmission in a particular requirement?

How is the most economical voltage selected for transmission in a particular requirement? Correct Answer Based on Kelvin’s law

Explanation:

Kelvin's law states that the most economical size of a conductor is that for which annual interest and depreciation on the capital cost of the conductor is equal to the annual cost of energy loss.

Graphical representation of Kelvin’s law:

Additional Information

  • Fleming's right-hand rule (generators): It shows the direction of induced current when a conductor attached to a circuit moves in a magnetic field. It can be used to determine the direction of current in a generator's windings.
    • The thumb is pointed in the direction of the motion of the conductor relative to the magnetic field.
    • The first finger is pointed in the direction of the magnetic field. (North to south).
    • Then the second finger represents the direction of the induced or generated current within the conductor (from the terminal with lower electric potential to the terminal with higher electric potential, as in a voltage source).

[ alt="RightHandOutline" right-hand rule wikipedia src="https://upload.wikimedia.org/wikipedia/commons/9/9a/RightHandOutline.png" style="border-width: 1px; border-style: solid; height: 219px; width: 300px;">

  • Fleming's left-hand rule (electric motors): When current flows through a conducting wire, and an external magnetic field is applied across that flow, the conducting wire experiences a force perpendicular both to that field and to the direction of the current flow (i.e. they are mutually perpendicular).
    • The Thumb represents the direction of the Thrust on the conductor / Motion of the Conductor.
    • The Forefinger represents the direction of the Magnetic Field.
    • The Centre finger represents the direction of the Current.

[ alt="300px-LeftHandOutline" left-hand rule for motors wikipedia src="https://upload.wikimedia.org/wikipedia/commons/thumb/1/15/LeftHandOutline.png/300px-LeftHandOutline.png" style="border-width: 1px; border-style: solid; height: 219px; width: 300px;">

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