Question

A 4$\Omega$ resistance is bent through 180${}^o$ at its midpoint and the two halves are twisted together. Then the resistance is

• A. 1$\Omega$
• B. 2$\Omega$
• C. 5$\Omega$
• D. 8$\Omega$

Answer 1

Answer: (A)

1$\Omega$

As the $4\Omega$ resistance is folded at its midpoint, thus the resistance of each segment which are now connected in parallel is $2\Omega$.

Equivalent resistance between A and B $\frac{1}{R_{AB}}=\frac{1}{2}+\frac{1}{2}$

$⟹$ $R_{AB}=1\Omega$