A potentiometer wire of length $10 \,m$ and resistance$20 \,\Omega$ is connected in series with a $25 \,V$ battery and an external resistance $30\, \Omega$. A cell of emf $E$ in secondary circuit is balanced by $250\, cm$ long potentiometer wire. The value of $E$ (in volt) is $\frac{x}{10}$. The value of $x$ is.......
JEE MAIN 2022, Medium
Download our app for free and get started
$I =\frac{25}{50}=\frac{1}{2} \,A$
$\therefore \Delta\, V =10 \,V$
$10 \,m \rightarrow 10 \,V$
$2.5\, m \rightarrow 2.5\, V$
Download our appand 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.*
Similar Questions
- 1A wire of resistance $4 \,\Omega$ is stretched to twice its original length. The resistance of stretched wire would be ........... $\Omega$View Solution
- 2The figure here shows a portion of a circuit. What are the magnitude and direction of the current i in the lower right-hand wire .................... $A$View Solution
- 3View SolutionSensitivity of potentiometer can be increased by
- 4A wire has a non-uniform cross-section as shown in figure.A steady current flows through it. The drift speed of electrons at points $P$ and $q$ is $v_P$ and $v_Q$.View Solution
- 5Assertion : All electric devices shown in the circuit are ideal. The reading of each of ammeter $(a)$ and voltmeter $(V)$ is zero.View Solution
Reason : An ideal voltmeter draws almost no current due to very large resistance, and hence $(V)$ and $(a)$ will read zero.
- 6In the circuit shown in figure, the heat produced in $5\, ohm $ resistance is $10\, cal / sec$ . The heat produced in $4$ resistance is ................ $cal /sec$View Solution
- 7The resistance in the two arms of a meter bridge are $5\,\Omega $ and $R\,\Omega $, respectively. When the resistance $R$ is shunted with an equal resistance, the new balance point is at $1.6\, l_1$. The resistance $‘R’$ is ................. $\Omega$View Solution
- 8In the given current distribution what is the value of $I$ .............. $A$View Solution
- 9Two identical batteries, each of $e.m.f.$ $2\, volt$ and internal resistance $1.0\, ohm$ are available to produce heat in an external resistance $R = 0.5\,ohm$ by passing a current through it. The maximum Joulean power that can be developed across $R$ using these batteries is ............. $watt$View Solution
- 10View SolutionThe internal resistance of a cell is the resistance of