NEET Solved Paper 2018 Question 6
Question: A set of ’n’ equal resistors, of value ‘R’ each, are connected in series to a battery of emf ‘E’ and internal resistance ‘R’. The current drawn is I. Now, the ’n’ resistors are connected in parallel to the same battery. Then the current drawn from battery becomes 10 I. The value of ’n’ is [NEET - 2018]
Options:
A) 20
B) 11
C) 10
D) 9
Show Answer
Answer:
Correct Answer: C
Solution:
- $ \text{I=}\frac{E}{\text{nR+R}} $ -(i) $ 10\text{I=}\frac{E}{\frac{R}{n}\text{+R}} $ -(ii)
Dividing (ii) by (i), $ \text{10=}\frac{\text{(n+1)R}}{( \frac{1}{n}\text{+1} )R} $
After solving the equation, $ \text{n=10} $
