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Three identical impedances (3 + j6) Ω are connected in delta to a three-phase, 50 Hz supply. What will be the equivalent star-connected impedance that draws the same current when connected to the same supply voltage?

Three identical impedances (3 + j6) Ω are connected in delta to a three-phase, 50 Hz supply. What will be the equivalent star-connected impedance that draws the same current when connected to the same supply voltage? Correct Answer (1 + j2) Ω

Delta to Star Conversion:

Shortcut Trick

  • If the values of all impedance in delta connection are equal, then in star equivalent, the value of impedance becomes one-third of its original value.
  • This is valid only for resistance and inductor.
  • In the case of capacitors, if the values of all capacitors in delta connection are equal, then in star equivalent, the value of capacitors becomes three times its original value.

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