Question

Five equal resistance, each of resistance $R$ are connected as shown in figure. A battery of $V$ volt is connected between $A$ and $B$. The current flowing in $FC$ will be

• A. $\frac{3V}{R}$
• B. $\frac{V}{R}$
• C. $\frac{V}{2R}$
• D. $\frac{2V}{R}$

Answer 1

Answer: (C)

$\frac{V}{2R}$

In fig (a), we get a balanced wheat stone bridge, i.e, $\frac{R}{R}=\frac{R}{R}=1$

Thus no current will pass through the middle resistance, so it acts as an open circuit.

Let current flowing through the points $FC$ in figure (b) be $i$.

Using Kirchhoff's voltage law for loop $QPAFCEB$:

$\Rightarrow -V+iR+iR=0$

$\Rightarrow$$i=\frac{V}{2R}$