Question

If a star connected system has equal impedances Z1, then after converting into delta connected system having equal impedances Z2, then?

(a) Z2 = Z1

(b) Z2 = 2Z1

(c) Z2 = 3Z1

(d) Z2 = 4Z1

I had been asked this question in a national level competition.

Enquiry is from Star to Delta and Delta to Star Transformation in section Polyphase Circuits of Network Theory

Answer 1

Correct answer is (c) Z2 = 3Z1

Explanation: If a star connected system has equal impedances Z1, then after converting into delta connected system having equal impedances Z2, then Z2 = 3Z1.