Question

Which of the following combinations have the same equivalent resistance between X and Y?

Answer 1

(a) Two resistors are in parallel,

$\frac{1}{R}=\frac{1}{2}+\frac{1}{2}=1R=1\Omega$

(b) Three resistors are in parallel,

$\frac{1}{R}=\frac{1}{1}+\frac{1}{1}+\frac{1}{2}=\frac{5}{2}R=\frac{2}{5}=0.4\Omega$

(c) Two resistors are in parallel,

$\frac{1}{R}=\frac{1}{1}+\frac{1}{1}=2R=\frac{1}{2}=0.5\Omega$

(d) two resistors series above,

R = 1+1 = 2

two resistors series below,

R = 1+1 = 2

They are parallel to each other.

$\frac{1}{R}=\frac{1}{2}+\frac{1}{2}=1R=1\Omega$

(a) and (d) have the same equivalent resistance between X and Y.