GATE 2014 EC (EC1) – Question 40

Networks, Signals and Systems · Two-Port Networks and Wye-Delta Transformation · 2 marks · Numerical answer

A Y-network has arm resistances 10 Ω,10 Ω,11 Ω. Find the lowest resistance (Ω) in its equivalent Δ-network.

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Correct answer: 29.08 to 29.10

Explanation

For star arms10,10,11Ω the pairwise-product sum is100+110+110=320Ω². Each delta arm equals this sum divided by the opposite star arm. The values are32,32 and320/11=**29.0909Ω**; the last is the smallest.