Infinite number of cells having $emf$ and internal resistance $\left( {E,r} \right)$, $\left( {\frac{E}{n},\frac{r}{n}} \right)$, $\left( {\frac{E}{{{n^2}}},\frac{r}{{{n^2}}}} \right)$, $\left( {\frac{E}{{{n^3}}},\frac{r}{{{n^3}}}} \right)$..... are connected in series in same manner across an external resistance of $\frac{{nr}}{{n + 1}}$ . Current flowing through the external resistor is
A$\frac{E}{{2r}}$
B$\frac{E}{{\left( {n - 1} \right)r}}$
C$\frac{{\left( {n - 1} \right)E}}{{2n}}$
D$\frac{{\left( {n + 1} \right)E}}{{2nr}}$
Diffcult
Download our app for free and get started
D$\frac{{\left( {n + 1} \right)E}}{{2nr}}$
d $I=\frac{E+\frac{E}{n}+\frac{E}{n^{2}}+\frac{E}{n^{3}} \ldots \ldots}{\left(r+\frac{r}{n}+\frac{r}{n^{2}}+\frac{r}{n^{3}}+\ldots\right)+\frac{n r}{n+1}}$
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.*
Two resistors $400\, \Omega$ and $800\, \Omega$ are connected in series across a $6 V$ battery. The potential difference measured by a voltmeter of $10\, k \Omega$ across $400\, \Omega$ resistor is close to$....V$
Three resistances $P, Q, R$ each of $2 \,\,\Omega$ and an unknown resistance $S$ form the four arms of a Wheatstone bridge circuit. When a resistance of $6 \,\,\Omega$ is connected in parallel to $S$ the bridge gets balanced. What is the value of $S\,?$ ............... $\Omega$
Two wires of same metal have the same length but their cross-sections are in the ratio $3:1$. They are joined in series. The resistance of the thicker wire is $10\,\Omega $. The total resistance of the combination will be ............. $\Omega$
The resistance of a wire is $R$. It is bent at the middle by $180^{\circ}$ and both the ends are twisted together to make a shorter wire. The resistance of the new wire is
A light bulb of resistance $R=16 \,\Omega$ is attached in series with an infinite resistor network with identical resistances $r$ as shown below. A $10 \,V$ battery drives current in the circuit. ............. $\Omega$ the value of $r$ such that the bulb dissipates about $1 \,W$ of power.
The resistance of the series combination of two resistance is $S$. When they are joined in parallel the total resistance is $P$. If $S = nP$, then the minimum possible value of $n$ is
Two batteries one of the $\mathrm{emf}$ $3\,V$, internal resistance $1$ ohm and the other of $\mathrm{emf}$ $15\, V$, internal resistance $2$ $\mathrm{ohm}$ are connected in series with a resistance $R$ as shown. If the potential difference between $a$ and $b$ is zero the resistance of $R$ in $\mathrm{ohm}$ is