On the Eastern sections of the Historic Columbia River Highway between Hood River and The Dalles the hillsides are now green in their sublime spring beauty. Wildflowers and wild grasses abound. Get out there in early spring, because the eastern Columbia River Gorge landscape is usually brown by the middle of May.
Magneto Motive Force is expressed as a current, I flowing through a coil of N turns. The magnetic field strength of an electromagnet is therefore determined by the ampere turns of the coil with the more turns of wire in the coil the greater will be the strength of the magnetic field.
Quick review: The coil is a big transformer with a magnetic core. Current from the battery goes into the primary winding on Terminal #15. That same current goes out Terminal #1 and through the point contacts. This current creates a magnetic field in the core of the coil.