Question

In the circuit shown, if key $K$ is open, then ammeter reading will be

• A. $50A$
• B. $2A$
• C. $0.5A$
• D. $\frac{10}{9}A$

Answer 1

The correct option is B $2A$

In the circuit shown, when key $K$ is open branch $BC$ will not be a part of the circuit $($i.e. not connected to the circuit having battery $)$. The current will not flow through the branch $BC$ having $4\Omega$ resistor. Hence the ammeter will read the current flowing through remaining circuit.
Therefore,
$I=\frac{V}{R}$
$I=\frac{10}{5}$
$I=2A$