Question

For the circuit given below, the value of the hybrid parameter h11 is ___________

(a) 15 Ω

(b) 20 Ω

(c) 30 Ω

(d) 25 Ω

I got this question during an interview.

Origin of the question is Hybrid (h) Parameter topic in section Two-Port Networks of Network Theory

Answer 1

Right choice is (a) 15 Ω

To elaborate: Hybrid parameter h11 is given by, h11 = \(\frac{V_1}{I_1}\), when V2=0.

Therefore short circuiting the terminal Y-Y’, we get,

 V1 = I1 ((10||10) + 10)

= I1 \(\left(\left(\frac{10×10}{10+10}\right)+10\right)\)

= 15I1

∴ \(\frac{V_1}{I_1}\) = 15.

Hence h11 = 15 Ω.