There is one metal wire of length l, which is broken in two parts of unequal length. One part is called A and the other, B. When the length of A is stretched to double its length then its resistance becomes equal to that of B. What is the original ratio of length of A to that of B?

Explanation

To solve the problem, we need to analyze the relationship between the resistances of the two parts of the wire, A and B, and how stretching affects their resistance.

### Step-by-Step Solution:

1. **Define the lengths of the wire parts:**
Let the length of part A be \( L_1 \) and the length of part B be \( L_2 \). The total length of the wire is given by:
\[
L = L_1 + L_2
...