Question

Four resistance each of R ohms and two resistances each of S ohms are connected (as shown in Fig.

2.50) to four terminasl AB and CD. A p.d. of V votls is applied across the terminals AB and a

resistance

Answer 1

To be given in question

Resistance

$R_1=R_2=R\Omega$

$R_3=R_4=S\Omega$

$R_1 andR_2$ Parallel combination

$R'=\frac{R_1 R_2}{R_1+R_2}$

$R'=\frac{R\times R}{R+R}=\frac{R}{2}\Omega$

Now

$R_3 and R_4 parallel combination$

$R''=\frac{R_3R_4}{R_3+R_4}$

$R''=\frac{S \times S}{S+S}=\frac{S}{2}$

$R_{eq}=R'+R''$

$R_{eq}=\frac{R}{2}+\frac{S}{2}$

$R_{eq}=\frac{R+S}{2}$