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 $.............\,\Omega$.
A$5$
B$4$
C$3$
D$2$
JEE MAIN 2023, Medium
Download our app for free and get started
A$5$
a $i=\frac{2 \varepsilon}{5+2 r}........(1)$
$i=\frac{\varepsilon}{\frac{r}{2}+5}.........(2)$
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.$5$
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Every atom makes one free electron in copper. If $1.1$ $ampere$ current is flowing in the wire of copper having $1\, mm$ diameter, then the drift velocity (approx.) will be (Density of copper $ = 9 \times {10^3}\,kg\,{m^{ - 3}}$ and atomic weight = $63$)
There are $8$ equal resistances $R$. Two are connected in parallel, such four groups are connected in series, the total resistance of the system will be
For a cell, the graph between the potential difference $(V) $ across the terminals of the cell and the current $(I)$ drawn from the cell is shown in the figure. The $e.m.f.$ and the internal resistance of the cell are