Question

A cell has terminal voltage $2\, V$ in open circuit and internal resistance of the given cell is $2Ω$. If $4\, A$ of current is flowing between points $P$ and $Q$ in the circuit and then the potential difference between $P$ and $Q$ is

• A. $30\, V$
• B. $26\, V$
• C. $22\, V$
• D. $24\, V$

Answer 1

Answer: (B)

Key Point Find the terminal potential difference in case of charging a battery.

According to question, it is the case of charging of battery. So, terminal potential difference is given by
$TPD =V_{P}-V_{R}= E+I_{r}=2+(4 \times 2)$
$=10\, V$ ...(i)
Again, $V_{R}-V_{Q}=4 \times 4=16\, V$ ...(ii)
From Eqs. (i) and (ii), we get
$V_{P}-V_{R}+V_{R}-V_{Q}=10+16$
$\Rightarrow V_{P}-V_{Q}=26\, V$