Question

In the circuit given below the value of resistance Req is _____________

(a) 10 Ω

(b) 11.86 Ω

(c) 11.18 Ω

(d) 25 Ω

Answer 1

The correct option is (c) 11.18 Ω

To explain I would say: The circuit is as shown in figure below.

Req = 5 + \(\frac{10(R_{eq}+5)}{10 + 5 + R_{eq}}\)

Or, (R_{eq}^2) + 15Req = 5Req + 75 + 10Req + 50

Or, \(R_{eq} = \sqrt{125}\) = 11.18 Ω.