Question

An electric bulb is rated as $10\text{W},220\text{V}$. How many of these bulbs can be connected in parallel across $220\text{V}$ supply if the maximum current which can be drawn is $5\text{A}$ ?

• A. $120$
• B. $110$
• C. $130$
• D. $140$

Answer 1

The correct option is B $110$

Power consumed by one bulb,

$P=10\text{W}$

The maximum power that the source can supply is :

$P_{\text{max}}=V{I}_{\text{max}}=220\times 5=1100\text{W}$

We know that in parallel combination of bulbs, net power consumed by the combination is equal to the sum of powers consumed by individual bulb.

Let $n$ is the maximum number of bulbs that can be connected.

$\Rightarrow P_{\text{max}}=nP$

$\Rightarrow n=\frac{P_{\text{max}}}{P}=\frac{1100}{10}$

$\Rightarrow n=110$ bulbs

​​​​​​​Hence, option $\left(B\right)$ is the correct answer.