Question

Two bulbs of equal power are connected in parallel and they totally consume $110W$ at $220V$ . The resistances of each bulb is

• A. $550\Omega$
• B. $440\Omega$
• C. $330\Omega$
• D. $880\Omega$

Answer 1

Answer: (D)

Bulbs are connected in parallel and they totally consume $110W$ at $220V$
Net power, $P_{net}=P_1+P_2$
$P+P=110W\left\{\because P_1=P_2=P\right\}$
$2P=110W\Rightarrow P=55W$
We know that,
$P=\frac{V^2}{R}$
$55=\frac{{\left(220\right)}^2}{R}$
$R=\frac{{\left(220\right)}^2}{55}=\frac{220\times 220}{55}=880\Omega$