Question

Find the reading of the ammeter$\left(A\right)$ as shown in the figure.

• A. $3\text{A}$
• B. $4\text{A}$
• C. $8\text{A}$
• D. $5\text{A}$

Answer 1

The correct option is B $4\text{A}$


Equivalent resistance of the circuit,

$R_{eq}=\frac{3\times 6}{3+6}+1=3\Omega$

Current through battery is,

$I=\frac{18}{3}=6\text{A}$

The potential difference across the ammeter and $6\Omega$ resistor is,

$V=IR=6\times \frac{6\times 3}{6+3}=12\text{V}$

So, current through the ammeter is,

$I_A=\frac{12}{3}=4\text{A}$

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, option $\left(B\right)$ is the correct answer.