Question

A 10 V is connected across a load whose V-I characteristics is given by 7I = V^2 + 2V. The internal resistance of the battery is of magnitude 1Ω. The current delivered by the battery is ____________ (a) 6 A (b) 5 A (c) 7 A (d) 8 A The question was posed to me during an interview for a job. I need to ask this question from Problems Involving Standard Time Functions topic in portion Application of the Laplace Transform in Circuit Analysis 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

Right answer is (b) 5 A Easiest explanation: 7I = V^2 + 2V …………………. (1) Now, V = 10 – 1 ×I Putting the value of V in eqt (1), we get, &I = (10 – I) 2 + 2(10 – I) Or, I = 100 + I2 – 20I + 20 – 2I Or, I2 – 29I + 120 = 0…………………. (2) ∴ I = \frac{+29 ± \sqrt{29^2 – 4(120)}}{2} = \frac{29 ± 19}{2} I = 5 A, 24 A Now, I = 24 A is not possible because V will be negative from eqt (2) ∴ I = 5 A.