What will be equivalent resistance of circuit between $x$ and $y$
A$R$
B$\frac {R}{2}$
C$\frac {8R}{3}$
D$\frac {13R}{5}$
Medium
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B$\frac {R}{2}$
b
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When a resistance of $2\,ohm$ is connected across the terminals of a cell, the current is $0.5$ amperes. When the resistance is increased to $5\, ohm$, the current is $0.25\, amperes$. The internal resistance of the cell is ............. $ohm$
Suppose a current carrying wire has a cross-sectional area that, gradually become smaller along the wire, has the shape of a very long cone as shown in figure. Choose the correct statement
An ammeter $A$ of finite resistance, and a resistor $R$ are joined in series to an ideal cell $C$. $A$ potentiometer $P$ is joined in parallel to $R$. The ammeter reading is $I_0$ and the potentiometer reading is $V_0$. $P$ is now replaced by a voltmeter of finite resistance. The ammeter reading now is $I$ and the voltmeter reading is $V$.
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For current entering at $A$, the electric field at a distance '$r$'
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