In a delta connection each phase is connected directly between two line conductors, so the phase voltage is exactly the line-to-line voltage: VL = Vph.
Formula / Key Relation
Delta:
VL = Vph
IL = √3 Iph
Star:
VL = √3 Vph
IL = Iph
Detailed Explanation
Concept & ReasoningA delta-connected load has each phase element across a pair of supply lines. Therefore the voltage across an individual phase is the same line-to-line voltage measured at the terminals. The √3 relationship in delta applies to current, not voltage: IL = √3 Iph (with a 30° phase displacement). In a star connection the voltage relationship is VL = √3 Vph.How to Solve It in the ExamDelta: voltage same, current √3. Star: current same, voltage √3.Important Exam PointWrite the star/delta pair together to avoid swapping the √3 factor.Related Revision PathThis question sits in the revision path Basic Electrical Engineering…
Concept & Reasoning
A delta-connected load has each phase element across a pair of supply lines. Therefore the voltage across an individual phase is the same line-to-line voltage measured at the terminals. The √3 relationship in delta applies to current, not voltage: IL = √3 Iph (with a 30° phase displacement). In a star connection the voltage relationship is VL = √3 Vph.
How to Solve It in the Exam
Delta: voltage same, current √3. Star: current same, voltage √3.
Important Exam Point
Write the star/delta pair together to avoid swapping the √3 factor.
Related Revision Path
This question sits in the revision path Basic Electrical Engineering → Three-Phase Circuits → Delta Connection .
Quick Trick
Delta: voltage same, current √3. Star: current same, voltage √3.
Common Mistake
Do not apply VL = √3Vph to a delta-connected load; that is the star-voltage relation.
Exam Tip
Write the star/delta pair together to avoid swapping the √3 factor.
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