Question

Explain why iron filings align to give the appearance of field lines when in a magnetic field How was the Gilley coil's magnetic field affected when the iron core was? (Hint: see Figure 2) Figure 2: As the magnetic field strength (H) increases from zero (a), the magnetic domains that are aligned parallel to it increase in size at the expense of their neighbouring domains (b), then whole domains start to switch (c) until all domains are aligned (d).

Answer 1

A) iron is one of the ferromagnetic material . so they strongly react to the magnetic fields. Each iron filling consists of a number of magnetic domains. These domains they try to lower their energy by lining up with their fields, as a result the filling as a whole allign itself to give the appearance of magnetic field lines.

B) when iron core was there then the magnetic field lines are more concentrated , i.e. the strength of the field was greater . which means that all the domains are oriented in the same direction.