Question

A circuit is given in the figure below. We can infer that ________

(a) The circuit follows Reciprocity Theorem

(b) The circuit follows Millman’s Theorem

(c) The circuit follows Superposition Theorem

(d) The circuit follows Tellegen Theorem

I had been asked this question during an interview for a job.

My question is from Advanced Problems on Reciprocity Theorem in section Useful Theorems in Circuit Analysis of Network Theory

Answer 1

Correct option is (a) The circuit follows Reciprocity Theorem

Easy explanation: Let us consider this circuit,

Rth = [(2+4) || 6] + 12 = 15 Ω

IS = \(\frac{45}{15}\) = 3 A

Now, by current division rule, we get, I1 = \(\frac{3 × 6}{12} = \frac{18}{12}\) = 1.5 A.

Again, let us consider this circuit,

Equivalent resistance,REQ = [(12 || 6) + 2 + 4] = 10 Ω

IS = \(\frac{45}{10}\) = 4.5 A

Now, by using Current division rule, we get, I2 = \(\frac{4.5 × 6}{12+6} = \frac{27}{18}\) = 1.5 A.

Since I1 = I2, the circuit follows Reciprocity Theorem.