n identical bulbs, each designed to draw power P from a certain source are joined in series across that supply. The total power drawn is

Question

n identical bulbs, each designed to draw power P from a certain source are joined in series across that supply. The total power drawn is (A) (P/n2) (B) (p/n) (C) P (D) n P

Tardigrade Admin · Accepted Answer

Resistance of each bulb, R = (V2/P) and Resistance of n bulbs in series = nR = (nV2/P) ∴ Power drawn when n bulbs are in serie = (V2/n × (V2)P) = (P/n)

Q. $n$ identical bulbs, each designed to draw power $P$ from a certain source are joined in series across that supply. The total power drawn is

$\frac{P}{n ^{2}}$

$\frac{p}{n}$

P

n P

Resistance of each bulb, R = $\frac{V ^{2}}{P}$ and Resistance of $n$ bulbs in series = $n$ R = $\frac{n V ^{2}}{P}$
$∴$ Power drawn when n bulbs are in serie = $\frac{V ^{2}}{n \times \frac{V ^{2}}{P}} = \frac{P}{n}$

Q. n identical bulbs, each designed to draw power P from a certain source are joined in series across that supply. The total power drawn is

n2P​

np​

P

n P

Resistance of each bulb, R = PV2​ and Resistance of n bulbs in series = nR = PnV2​ ∴ Power drawn when n bulbs are in serie = n×PV2​V2​=nP​

Q. $n$ identical bulbs, each designed to draw power $P$ from a certain source are joined in series across that supply. The total power drawn is

$\frac{P}{n ^{2}}$

$\frac{p}{n}$

Resistance of each bulb, R = $\frac{V ^{2}}{P}$ and Resistance of $n$ bulbs in series = $n$ R = $\frac{n V ^{2}}{P}$
$∴$ Power drawn when n bulbs are in serie = $\frac{V ^{2}}{n \times \frac{V ^{2}}{P}} = \frac{P}{n}$