Question

What is the equivalent resistance between A and B in the circuit of figure if $R=3\Omega$.

• A. $8\Omega$
• B. $6\Omega$
• C. $7\Omega$
• D. $9\Omega$

Answer 1

The correct option is A $8\Omega$

Effective resistance of the resistance between C and $D=\frac{R\times 2R}{R+2R}=\frac{2}{3}R$
(Two resistors are in series, the combination of which is in parallel with the third one)
Total resistance between A and $B=R+\frac{2}{3}R+R$
$=\frac{8}{3}R$
Given, $R=3\Omega$
Therefore, total resistance $=\frac{8}{3}\times 3=8\Omega$