Question

The value of equivalent resistance between the points $AandB$ in the given circuit, will be

• A. $6R$
• B. $\frac{4R}{11}$
• C. $\frac{11R}{4}$
• D. $\frac{R}{6}$

Answer 1

The correct option is C $\frac{11R}{4}$

$\text{Refer image-1}$

In the given circuit resistor cd, de and ef are in series.

$\therefore R_{eq}=cd+de+ef=R+R+R=3R$

Now, the circuit will be like $\text{Refer image-2}$

$\text{Refer image-2}$

In this circuit cf and de are parallel

$\therefore R_{eq}=\frac{R_{cf}\times R_{de}}{R_{cf}+R_{de}}$

$=\frac{R\times 3R}{R+3R}$

$=\frac{3R}{4}$

Now, the circuit will be like $\text{Refer image-3}$

$\text{Refer image-3}$

In this circuit, $Ac,cf,fB$ are in series

$\therefore R_{AB}=R+\frac{3R}{4}+R=2R+\frac{3R}{4}=\frac{11R}{4}$

$\therefore$ Correct option is C.