Question

What is the equivalent resistance of the arrangement of $5.0ohm$ resistors pictured in figure?

• A. $20.0ohms$
• B. $5.0ohms$
• C. $15ohms$
• D. $12.5ohms$
• E. $7.5ohms$

Answer 1

Answer: (D)

$12.5ohms$

Two resistors, each of $5\Omega$ are in parallel combination , therefore their equivalent resistance ,

$R=\frac{5.0\times 5.0}{5.0+5.0}=2.5\Omega$ ,

now all the resistors (including equivalent resistance $2.5\Omega$) are in series so equivalent resistance of the circuit ,

$R^{\prime }=5.0+2.5+5.0=12.5\Omega$