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)

Electric power, $p=i^{2} R$
$\therefore$ Current, $I=\sqrt{\frac{p}{R}}$
Fro resistance of $9 \Omega$
$i_{1}=\sqrt{\frac{36}{9}}=\sqrt{4}=2 A$
$i_{2}=\frac{i_{1} \times R}{6}=\frac{2 \times 9}{6}=3 A$
$i-i_{1}+i_{2}=2+3=5 A $
$V_{2}=I R_{2}=5 \times 2=10 V$