What is the magnetic induction at the mid-point of the straight line joining the two poles of a horse shoe magnet , separated by a distance '2d' ? (The pole strength of each pole is 'm'. )

Explanation

To find the magnetic induction at the midpoint of the straight line joining the two poles of a horseshoe magnet, we can follow these steps:

### Step 1: Understand the Setup
We have a horseshoe magnet with two poles: a north pole (N) and a south pole (S). The distance between the two poles is given as \(2d\). The midpoint (O) is located at a distance \(d\) from each pole.

### Step 2: Determine the Magnetic Induction Due to Each Pole
The magnetic induction \(B\) at a point due to a magnetic pole can be calculated using the formula:
\[
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