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} $
