Current Electricity Question 16
Question 16 - 31 January - Shift 1
Two identical cells, when connected either in parallel or in series gives same current in an external resistance $5 \Omega$. The internal resistance of each cell will be $\Omega$.
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Answer: (5)
Solution:
Formula: Cells in Parallel
Parallel
$i=\frac{2 \varepsilon}{5+2 r}$
Equating (1) and (2)
$\frac{2 \varepsilon}{5+2 r}=\frac{\varepsilon}{\frac{r}{2}+5} \Rightarrow r+10=5+2 r$
$r=5$ Ans. 5
