Question

When all the resistances in the circuit are 1 $\Omega$ each, then the equivalent resistance across points A & B will be

• A. 5/6 $\Omega$
• B. 1/2 $\Omega$
• C. 2/3 $\Omega$
• D. 1/3 $\Omega$

Answer 1

The correct option is D 1/3 $\Omega$

Since $R_1$ and $R_2$ are short circuit,the circuit can be re arrange(see figure-2).Now all resistance are in paralell, So Equivalent Resistance can be found using formula for parallel combination.

$\frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}+......$

$\Rightarrow$$\frac{1}{R_{eq}}=\frac{1}{1}+\frac{1}{1}+\frac{1}{1}$

$\Rightarrow R_{eq}=\frac{1}{3}\Omega$

Therefore, D is correct answer.