A resistance of $4\,\Omega $ and a wire of length $5\,m$ and resistance $5\,\Omega $ are joined in series and connected to a cell of $e.m.f.$ $10\, V$ and internal resistance $1\,\Omega $. A parallel combination of two identical cells is balanced across $300\, cm$ of the wire. The $e.m.f.$ $E$ of each cell is ........... $V$
A$1.5$
B$3$
C$0.67$
D$1.33$
Medium
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B$3$
b $E = x\,l = \frac{V}{l} = \frac{{iR}}{L} \times l$
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In the following circuit, $18\,\Omega $ resistor develops $2\,J/sec$ due to current flowing through it. The power developed across $10\,\Omega $ resistance is .............. $W$
Potentiometer wire of length $1 \,m$ is connected in series with $490\,\Omega $ resistance and $2\,V$ battery. If $0.2\, mV/cm $ is the potential gradient, then resistance of the potentiometer wire is ................ $\Omega$
In a potentiometer arrangement, a cell gives a balancing point at $75\, cm$ length of wire. This cell is now replaced by another cell of unknown emf. If the ratio of the emf's of two cells respectively is $3: 2$, the difference in the balancing length of the potentiometer wire in above two cases will be.........$cm .$
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{{J_0}\left( {\frac{x}{R} - 1} \right)\,\,for\,\,0 \leqslant x < \frac{R}{2}} \\
{{J_0}\frac{x}{R}\,\,\,\,for\,\,\,\frac{R}{2} \leqslant x \leqslant R}
\end{array}} \right.$The current flowing in the wire is:
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