Combination of Batteries: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Combination of Batteries. Understanding the underlying formula is key to arriving at the correct answer below:

The open-circuit balancing length is $l_1 = 110\text{ cm}$ and closed-circuit balancing length is $l_2 = 100\text{ cm}$.
Using internal resistance formula $r = R \left(\frac{l_1}{l_2} - 1\right)$:
$r = 10 \cdot \left(\frac{110}{100} - 1\right) = 10 \cdot 0.1 = 1.0\text{ ohm}$.