Question

In the circuit given below, the value of the Inverse hybrid parameter g21 is _________

(a) 10 Ω

(b) 0.5 Ω

(c) 5 Ω

(d) 2.5 Ω

I have been asked this question in exam.

The origin of the question is Inverse Hybrid (g) Parameter topic in portion Two-Port Networks of Network Theory

Answer 1

Right choice is (b) 0.5 Ω

Best explanation: Inverse Hybrid parameter g21 is given by, g21 = \(\frac{V_2}{V_1}\), when I2 = 0.

Therefore short circuiting the terminal Y-Y’, and applying Kirchhoff’s law, we get,

V1 = I1 (5 + 5)

V2 = I1 5

∴ \(\frac{V_2}{V_1}  = \frac{I_1 5}{I_1 10}\) = 0.5

 Hence g21 = 0.5 Ω.