NEET Solved Paper 2018 Question 7
Question: A battery consists of a variable number ’n’ of identical cells (having internal resistance ‘r’ each) which are connected in series. The terminals of the battery are shortcircuited and the current I is measured. Which of the graphs shows the correct relationship between I and n? [NEET  2018]
Options:
A)
B)
C)
D)
Show Answer
Answer:
Correct Answer: C
Solution:

Equivalent Emf: $ \varepsilon = n \varepsilon. $ Equivalent resistance: R = n r

$ \text{I=}\frac{n\varepsilon }{nr}\text{=}\frac{\varepsilon }{r} $ So, I is independent of n and I is constant.