Question:
A three-phase balanced voltage is applied to the load shown. The phase sequence is RYB. The ratio \(\left|\frac{I_B}{I_R}\right|\) is \(\underline{\hspace{1cm}}\).
A three-phase balanced voltage is applied to the load shown. The phase sequence is RYB. The ratio \(\left|\frac{I_B}{I_R}\right|\) is \(\underline{\hspace{1cm}}\).
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In balanced three-phase circuits, the magnitude of all phase currents is identical even if reactances differ in sign.
Updated On: Dec 29, 2025
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Correct Answer: 1
Solution and Explanation
Balanced supply → equal magnitude phase voltages.
Load impedances: \[ Z_R = -j10\Omega, Z_B = j10\Omega, Z_Y = j10\Omega. \] Magnitudes are equal: \[ |Z_R| = |Z_B| = |Z_Y| = 10\Omega. \] Thus line currents have equal magnitude: \[ |I_R| = |I_B| = |I_Y|. \] Therefore, \[ \left|\frac{I_B}{I_R}\right| = 1. \]
Load impedances: \[ Z_R = -j10\Omega, Z_B = j10\Omega, Z_Y = j10\Omega. \] Magnitudes are equal: \[ |Z_R| = |Z_B| = |Z_Y| = 10\Omega. \] Thus line currents have equal magnitude: \[ |I_R| = |I_B| = |I_Y|. \] Therefore, \[ \left|\frac{I_B}{I_R}\right| = 1. \]
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