Question

A main line has power $11kW$ the maximum number of $100W$ bulbs which can be connected for full glow are
(A) $10$ In series
(B) $100$ In parallel
(C) $110$ In parallel
(D) $60$ In parallel or series

Answer 1

In order to solve this question, we will first calculate the power of n number of bulbs in series combination and parallel combination separately with the concept that, in series combination current is same for each component whereas voltage is same in parallel combination, so we will use separate formula for series and parallel combination of power then determine the number of maximum bulbs that can be connected with given main line power.

Complete step-by-step solution:
We have given that, Main line has $Power = 11kW = 11000W$
Power of each bulb $P = 100W$
Now, Number of $100W$ bulbs that can be connected for main supply we will divide total power by power of each bulb,
$11000 = n \times 100$
$n = 110$
Now, we have seen that in order to glow the $100W$ bulbs we can connect $110$ bulbs either in series or in parallel but as we know that, in series combination voltage gets distributed so, lesser the voltage bulbs will not glow with full potential while in parallel combination each bulb will get same voltage so, they will glow with maximum intensity, so we will connect these number of bulbs in parallel combination.
Hence, the correct option is (C) $110$ in parallel.

Note: It should be remembered that, whether we connect all bulbs in series combination or in parallel combination, the bulbs will glow and the total main line of power will be used to glow all bulbs, only difference is the intensity of light of each bulb due to series and parallel combination. Power formula of electrical components is calculated using formula $P = {i^2}R$ and $P = \dfrac{{{V^2}}}{R}.$