Question 191 of 380

To verify Ohm’s law, a student connects the voltmeter across the battery as shown in the figure. The measured voltage is plotted as a function of the current, and the following graph is obtained:

If ${V}_{o}$ is almost zero, identify the correct statement:

AThe emf of the battery is $1.5V$ and its internal resistance is $1.5\Omega$BThe value of the resistance $R$ is $1.5\Omega$CThe potential difference across the battery is $1.5V$ when it sends a current of $1000mA$DThe emf of the battery is $1.5V$ and the value of $R$ is $1.5\Omega$

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Answer: (A) The emf of the battery is $1.5V$ and its internal resistance is $1.5\Omega$

$V=E-Ir$
when $V={V}_{0}=0\Rightarrow 0=E-Ir$
$∴E=Ir$
when $I=0,V=E=1.5V$
$∴r=1.5\Omega .$