Question

In the given question, a statement of Assertion $\left(A\right)$ is given, followed by a corresponding statement of Reason $\left(R\right)$ just below of it. Mark the correct answer.

Assertion$\left(A\right)$ : To draw more current at low potential difference through a low external resistance, parallel connection of identical cells is preferred.

Reason$\left(R\right)$ : In parallel connection, current $i=\frac{nE}{r}$, if $r>>R$
[where $r$-internal resistance, $E$ - emf of the cell and $n$ - number of cells]

• A. Both $\left(A\right)$ and $\left(R\right)$ are true and $\left(R\right)$ is the correct explanation of $\left(A\right)$
• B. Both $\left(A\right)$ and $\left(R\right)$ are true and $\left(R\right)$ is not the correct explanation of $\left(A\right)$
• C. $\left(A\right)$ is true and $\left(R\right)$ is false
• D. $\left(A\right)$ is false and $\left(R\right)$ is true

Answer 1

The correct option is B Both $\left(A\right)$ and $\left(R\right)$ are true and $\left(R\right)$ is not the correct explanation of $\left(A\right)$

When identical cells are connected in parallel, the current through the external resistance is,

$i=\frac{E}{R+\left(\frac{r}{n}\right)}$

If $R<<r$ then,

$i=\frac{E}{\left(\frac{r}{n}\right)}$

$i=\frac{nE}{r}$

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(A\right)$ is the correct answer.