Question

In the circuit given E = 6.0 V, $R_1=100\Omega ,R_2=R_3=50\Omega ,R_4=75\Omega$. The equivalent resistance of the circuit, in $\Omega$ , is

• A. $11.875$
• B. $26.31$
• C. $18.75$
• D. $263.1$

Answer 1

The correct option is C $18.75$

In given circuit three resistance $R_2{R}_4$ and $R_3$ are parallel.

$\frac{1}{R}=\frac{1}{R_2}+\frac{1}{R_4}+\frac{1}{R_3}$

$=\frac{1}{50}+\frac{1}{50}+\frac{1}{75}$

$=\frac{75+75+50}{50\times 75}$

$R=\frac{50\times 75}{75+75+50}=\frac{50\times 75}{200}=\frac{75}{4}\Omega =18.75\Omega$

Thus resistance is in series with $R_1$