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 short-circuited 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.