Question

Find the equivalent resistance at node A in the delta connected circuit shown in the figure below.

(a) 1

(b) 2

(c) 3

(d) 4

I have been asked this question during an interview.

I'm obligated to ask this question of Star-Delta Transformation in chapter Useful Theorems in Circuit Analysis of Network Theory

Answer 1

The correct answer is (d) 4

To explain: Performing delta to star transformation we obtain the equivalent resistance at node A is R =(11×12)/(11+12+13)=4Ω.