Question

A circuit consists of an excitation voltage VS, a resistor network and a resistor R. For different values of R, the values of V and I are as given, R = ∞, V = 5 volt; R = 0, I = 2.5 A; when R = 3 Ω, the value of V is __________ (a) 1 V (b) 2 V (c) 3 V (d) 5 V The question was asked in a national level competition. My doubt stems from Advanced Problems Involving Complex Circuit Diagram topic in portion Network Theory and Complex Circuit Diagram of Network Theory Select the correct answer from above options network theory questions and answers, network theory questions pdf, network theory question bank, network theory gate questions and answers pdf, mcq on network theory pdf, gate network theory questions and solutions, network theory mcq Test , ies network theory questions, Network theory Questions for GATE EC Exam, Network Theory MCQ (Multiple Choice Questions)

Answer 1

Correct choice is (c) 3 V The explanation: When R = ∞, V = 5v, Then, Voc = 5V and the circuit is open When R = 0, I = 2.5A Then, Isc = 2.5 and the circuit is short circuited. So, Req = \frac{V_{OC}}{I_{SC}} = \frac{5}{2.5} = 2 Ω Hence the voltage across 3 Ω is 3 volt.