### NEET Solved Paper 2019 Question 34

##### Question: Six similar bulbs are connected as shown in the figure with a DC source of emf E and zero internal resistance. The ratio of power consumption by the bulbs when (i) all are glowing and (ii) in the situation when two from section A and one from section B are glowing, will be-[NEET 5-5-2019]

#### Options:

A) 1 : 2

B) 2 : 1

C) 4 : 9

D) 9 : 4

## Show Answer

#### Answer:

Correct Answer: D

#### Solution:

When all bulbs are glowing $ R _{eq}=\frac{R}{3}+\frac{R}{3}=\frac{2R}{3} $

$ Power,P _1=\frac{3E^{2}}{2R} $ —————– (i)

In case two $ R _{eq}=\frac{3R}{2} $

$ Power,P _2=\frac{2E^{2}}{3R} $ ————— (ii)

$ \frac{P _1}{P _2}=\frac{3}{2}\times \frac{3}{2}=\frac{9}{4} $