Q140 / 155 · WBJEE 2020 · Physics

What will be the equivalent resistance between the terminals A and B of the infinite resistive network shown in the figure?

What will be the equivalent resistance between the terminals A and B of the infinite resistive network shown in the figure?
- A$\frac{(\sqrt{3}+1) \mathrm{R}}{2}$
- B$\frac{(\sqrt{3}-1) R}{2}$
- C$3 \frac{R}{2}$
- Correct answerD$(\sqrt{3}+1) \mathrm{R}$
Solution
Hint:

$x=2 R+\frac{R x}{R+x}$ $x^{2}-2 R x-2 R^{2}=0$ $x=(1+\sqrt{3}) R$

$x=2 R+\frac{R x}{R+x}$ $x^{2}-2 R x-2 R^{2}=0$ $x=(1+\sqrt{3}) R$
Hence, the correct answer is option: 'D'.