Question

A battery of $6\,V$ and internal resistance $2 \Omega$ is connected to a silver voltameter. If the current of $1.5\, A$ flows through the circuit, the resistance of the voltameter is

• A. $4\, \Omega$
• B. $2\, \Omega$
• C. $6\, \Omega$
• D. $1\, \Omega$

Answer 1

Answer: (B)

$2\, \Omega$

Answer 2

Given,
$E=-6 V, \, r=2 \Omega$ and $i=1.5\, A$
We know that, current across a circuit,
$i =\frac{E}{r +R}$
$\Rightarrow 1.5 =\frac{6}{2+R}$
$\Rightarrow 2+R =\frac{6}{1.5}$
or, $R =4-2=2 \Omega$