Question

Two resistors are joined in parallel whose resultant is $\frac{6}{5}\, \Omega$. One of the resistance wire is broken and the effective resistance becomes $2$ ohms. Then the resistance (in ohm) of the wire that got broken is

• A. $\frac{6}{5}$
• B. $2$
• C. $\frac{3}{5}$
• D. $3$

Answer 1

Answer: (D)

$\frac{R_{1} R_{2}}{R_{1}+R_{2}}=\frac{6}{5}$
$R_{1}=2$
$\frac{2 R_{2}}{2+R_{2}}=\frac{6}{5}$
$5 R_{2}=6+3 R_{2}$
$2 R_{2}=6$
$R_{2}=3 \,\Omega$