Question

Find the equivalent star network.

(a) 2.3ohm, 2.3ohm, 2.3ohm

(b) 1.2ohm, 1.2ohm, 1.2ohm

(c) 3.3ohm, 3.3ohm, 3.3ohm

(d) 4.5ohm, 4.5ohm, 4.5ohm

I got this question in final exam.

I would like to ask this question from Delta Star Transformation topic in division Network Theorems of Basic Electrical Engineering

Answer 1

The correct answer is (b) 1.2ohm, 1.2ohm, 1.2ohm

The explanation: The 6 ohm and 9 ohm resistances are connected in parallel. Their equivalent resistances are: 6*9/(9+6)=3.6 ohm.

The 3 3.6 ohm resistors are connected in delta. Converting to star:

R1=R2=R3= 3.6*3.6/(3.6+3.6+3.6)=1.2 ohm.