Question

If the ammeter in the given circuit reads 2 A, the resistance R is :-

Answer 1

From the figure,

Voltage, $V=6V$

Current, $I=2A$

Resistor 3 ohms and 6 ohms are in parallel. So,

$\frac{1}{r}=\frac{1}{3}+\frac{1}{6}$

$r=2\Omega$

Now, 2 ohms and r are in series, so

$R=2+r$

Since,

$R=\frac{V}{I}$

$2+r=\frac{6}{2}$

$r=1\Omega$