Consider the electromagnetic plunger shown in Figure P12.4.1. The λ-i relationship for the normal working range is experimentally found to be λ = K i2/3/(x +t), where K is a constant. Determine the electromagnetic force on the plunger by the application of Equations (12.4.19) and (12.4.20). Interpret the significance of the sign that you obtain in the force expression.
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