Question

Current measured by the ammeter Ⓐ in the reported circuit when no current flows through 10 Ω resistance, will be ___ A.

Fig. Circuit

Answer 1

The correct answer is 10
By using the condition of a balanced wheat stone bridge, we get
$⇒ \frac{R}{3} =\frac{4}{6} ⇒ 2Ω$
Therefore , the effective resistance of the circuit is
$R_{eq} = \frac{6×9}{6+9} = \frac{18}{5} Ω$
$i = \frac{36}{R_{eq}} = 10 A$