Question

Figure shows three resistor configurations $R_{1}, R_{2}$ and $R_{2}$ connected to $3 V$ battery. If the power dissipated by the configuration $R_{1}, R_{2}$ and $R_{3}$ is $P_{1}, P_{2}$ and $P_{3}$, respectively, then

• A. $P_{1}>P_{2}>P_{3}$
• B. $P_{1}>P_{3}>P_{2}$
• C. $P_{2}>P_{1}>P_{3}$
• D. $P_{3}>P_{2}>P_{1}$

Answer 1

Answer: (C)

$P_{2}>P_{1}>P_{3}$

Answer 2

Applying $P=\frac{V^{2}}{R}$,
$R_{1}=1 \,\Omega$
$R_{2}=0.5 \,\Omega$
and $R_{3}=2 \, \Omega$
$V_{1}=V_{2}=V_{3}=3 V$
$\therefore P_{1}=\frac{(3)^{2}}{1}=9 \,W$
$P_{2}=\frac{(3)^{2}}{0.5}=18 \, W$
and $P_{3}=\frac{(3)^{2}}{2}=4.5 \, W$
$\therefore P_{2} > P_{1} > P_{3}$