Question

The current passing through the ideal ammeter in the circuit given below is

• A. 1.25 A
• B. 1 A
• C. 0.75 A
• D. 0.5 A

Answer 1

Answer: (D)

0.5 A

Answer 2

Here, $2 \Omega$ and $2 \Omega$ are in parallel
$\therefore \frac{1}{R}=\frac{1}{2}+\frac{1}{2}$
$R=\frac{2 \times 2}{2+2}= 1 \,\Omega$
Now, internal resistance $(1\, \Omega), 2 \,\Omega, 4\, \Omega$ and resistance $R$ are in series
$\therefore R_{n e t}=1 \Omega+2 \Omega+4 \Omega+\lfloor\Omega=8 \Omega$
Hence, current $I=\frac{V}{R}=\frac{4}{8}=0.5 A$