Question

If power dissipated in the $9\, \Omega$ resistor in the circuit shown is $36$ watt, the potential difference across the $2\, \Omega$ resistor is

• A. 4 volt
• B. 8 volt
• C. 10 volt
• D. 2 volt

Answer 1

Answer: (C)

10 volt

Answer 2

$\because \rho= I _{ g }^{2} R$
$36= I ^{2}(9)$
$\Rightarrow I _{9}=2 A$
$\because$ In parallel $I \propto \frac{1}{ R }$
$\frac{ I _{9}}{ I _{6}}=\frac{6}{9} \,\,\,\,\,\frac{2}{ I _{6}}=\frac{6}{9}$
$I _{6}=3 A$
$\Rightarrow I _{ ckt }=2+3=5 A$
$\Rightarrow V\, _{2 \Omega}= IR =(5)(2)=10 \,volt$