Question

The terminal voltage of the battery, whose emf is$10V$ and internal resistance $1$, when connected through an external resistance of $42$ as shown in the figure is:

• A. $4 V$
• B. $6 V$
• C. $8 V$
• D. $10 V$

Answer 1

Answer: (C)

$8 V$

Answer 2

The terminal voltage is given by:
$V_{terminal} = E - Ir$
where $E$ is the emf, $I$ is the current, and $r$ is the internal resistance.
- Total resistance, $R_\text{total} = 4 \, \Omega + 1 \, \Omega = 5 \, \Omega$.
- Current, $I = \frac{E}{R_total} = \frac{10}{5} = 2 \, A$.
- Terminal voltage, $V_{terminal} = 10 - 2 \times 1 = 8 \, V$.