To determine the resistance ($R$) of a wire, a circuit is designed below, The $V-I$ characteristic curve for this circuit is plotted for the voltmeter and the ammeter readings as shown in figure. The value of $\mathrm{R}$ is . . . . . . .$\Omega$
A$2400$
B$2500$
C$2600$
D$2700$
JEE MAIN 2024, Diffcult
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B$2500$
b $\text { Req }=\frac{10^4 R}{10^4+R}$
$E=4 V, I=2 m A$
$I=\frac{E}{R e q} \Rightarrow 2 \times 10^{-3}=\frac{4\left(10^4+R\right)}{10^4 R}$
$\Rightarrow 20 R=40000+4 R$
$\quad 16 R=40000$
$R=2500 \Omega$
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