A straight conductor is split into indentical semicircular turns by tearing it into two parts from within. A current enters at one end and after passing through two parts leaves at the other, the field at the centre of the loop of radius r is :

Explanation

To find the magnetic field at the center of a loop formed by splitting a straight conductor into two identical semicircular turns, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Configuration**:
- We have a straight conductor that is split into two identical semicircular arcs.
- A current \( I \) enters at one end and exits at the other end after passing through both arcs.

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