Question

Eight cells marked $1$ to $8$ , each of emf $5\, V$ and internal resistance $0.2 \,\Omega$ are connected as shown. What is the reading of ideal voltmeter?

• A. 40 V
• B. 20 V
• C. 5 V
• D. Zero

Answer 1

Answer: (D)

Current flowing in circuit
$i=\frac{n E}{n r}=\frac{5}{0.2}=25 A$
Terminal potential difference across the terminals of battery numbered 8 ,
$V=E-i r=5-25 \times 0.2=0 $
$V=0$
Hence, voltmeter reading is zero. So, choice