Seems to be almost a textbook task from a freshmen class. But I am truly puzzled.
Electromagnet has a coil of tightly wound 100 turns of copper wire around a cylinder core with relative permeability of 600. Size of the core is : width (diameter) 30mm, length 10mm (wire wound around it's wide diameter, it is wider than long). Voltage applied 12v resulting in measured current 0.2A - this should make the wire fully defined for the purpose of solving this problem. For simplicity sake number of the wire layers can be ignored.
How to go about finding field intensity and flux density ?