SOLUTION

In attraction-type moving iron instruments, the soft iron piece is typically oval-shaped for several important reasons:

• Effective Magnetic Field Interaction: The oval shape allows the soft iron piece to interact more effectively with the magnetic field produced by the coil. This design helps to evenly distribute the magnetic field, which maximizes the attractive force.
• Precise Deflection: The oval shape enables the soft iron piece to rotate in a specific and predictable direction, providing precise deflection that is crucial for accurate measurements.
• Controlled Movement: Thanks to its oval shape, the soft iron piece can rotate smoothly and in a controlled manner, enhancing the instrument’s sensitivity and accuracy. Reduction of Non-
• Linear Scale: The oval shape contributes to a more uniform response to changes in the magnetic field, helping to minimize the problem of a non-linear scale.