Question

A resistance and an inductance are connected in parallel and fed from 50 Hz ac mains. Each branch takes a current of 5 A. The current supplied by source is ____________

(a) 10 A

(b) 7.07 A

(c) 5 A

(d) 0 A

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

The question is from Relation between Hybrid Parameters with Short Circuit Admittance and Open Circuit Impedance Parameters in chapter Two-Port Networks of Network Theory

Answer 1

Right choice is (b) 7.07 A

Easy explanation: The current is given by,

|5 – j5| = \(\sqrt{5^2 + 5^2}\)

= \(\sqrt{50} = 5\sqrt{2}\) = 7.07 A.