Question

The current through the ammeter shown in figure is $1A$. If each of the $4\Omega$ is resistor by $2\Omega$ resistor, the current in circuit will become nearly :

• A. $\frac{10}{9}A$
• B. $\frac{5}{4}$
• C. $\frac{9}{8}A$
• D. $\frac{5}{8}A$

Answer 1

The correct option is A $\frac{10}{9}A$

Let make the equivalent circuit as shown in figure.

$\Rightarrow R_1=2\Omega$,

$\Rightarrow \frac{1}{R_2}=\frac{1}{4}+\frac{1}{4}$ $\Rightarrow R_2=2\Omega$

$\Rightarrow \frac{1}{R_3}=\frac{1}{15}+\frac{1}{15}+\frac{1}{15}$ $\Rightarrow R_3=5\Omega$

$\therefore$ $R_{Equivalent}=R_1+R_2+R_3=9\Omega$

$I=\frac{V}{R}$ $\Rightarrow I=\frac{10}{9}A$