Question

In the circuit given below, it is given that VAB = 4 V for RL = 10 kΩ and VAB = 1 V for RL = 2kΩ. The value of Norton resistance for the network N is ____________

(a) 16 kΩ

(b) 30 kΩ

(c) 3 kΩ

(d) 50 kΩ

The question was posed to me by my college director while I was bunking the class.

My question is from Norton’s Theorem Involving Dependent and Independent Sources in section Useful Theorems in Circuit Analysis of Network Theory

Answer 1

Right answer is (b) 30 kΩ

The best I can explain: When RL = 10 kΩ and VAB = 4 V

Current in the circuit \(\frac{V_{AB}}{R_L} = \frac{4}{10}\) = 0.4 mA

Norton voltage is given by VN = I (RN + RL)

= 0.4(RN + 10)

= 0.4RN + 4

Similarly, for RL = 2 kΩ and VAB = 1 V

So, I = \(\frac{1}{2}\) = 0.5 mA

VN = 0.5(RN + 2)

= 0.5 RN + 1

∴ 0.1RN = 3

Or, RN = 30 kΩ.