Q. In the following circuit, $5\Omega$ resistor develops $45\ J/s$ due to current flowing through it. The power developed per second across $12\ \Omega$ resistor is
A) $16\ W$
B) $192\ W$
C) $36\ W$
D) $64\ W$
Explanation
(b) $\frac{i_{1}}{i_{2}} = \frac{15}{5} = \frac{3}{1}\ \ \ \ldots(i)$
Also$\ \frac{H}{t} = i^{2}R \Rightarrow 45 = \left( i_{1} \right)^{2} \times 5$
$\Rightarrow i_{1} = 3\ A\ $and from equation (i) $i_{2} = 1\ A$
So$\ i = i_{1} + i_{2} = 4\ A$
Hence power developed in $12\ \Omega$ resistance
$P = i^{2}R = (4)^{2} \times 12 = 192W$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.