A conductor AB of length 10 cm at a distance of 10 cm from an infinitely long parallel conductor carrying a current 10A. What work must be done to move AB to a distance of 20cm if it carries 5A?

Explanation

To solve the problem, we need to calculate the work done to move a conductor AB carrying a current of 5 A from a distance of 10 cm to a distance of 20 cm from an infinitely long parallel conductor carrying a current of 10 A.

### Step-by-Step Solution:

1. **Identify the Given Values:**
- Length of conductor AB, \( L = 10 \, \text{cm} = 0.1 \, \text{m} \)
- Current in conductor AB, \( I_2 = 5 \, \text{A} \)
- Current in the infinitely long conductor, \( I_1 = 10 \, \text{A} \)
...