As H increases into saturation, what happens to B?

As H increases into saturation, what happens to B?

• A. B increases linearly with H.
• B. B approaches a maximum value and increases slowly.
• C. B decreases as H increases.
• D. B becomes zero.

Answer: (B)

As you push a ferromagnetic material with a higher external field, the magnetic domains align more, so the flux density B rises. But this can’t go on forever—the magnetization M approaches a maximum value, Ms, once all the domains are largely aligned. When M is near this saturation value, further increases in H produce only small additional changes in B. So B climbs quickly at first, then levels off toward a maximum value (the saturation flux density) and rises only slowly as H increases further. That’s why the best description is that B approaches a maximum value and increases slowly.

As you push a ferromagnetic material with a higher external field, the magnetic domains align more, so the flux density B rises. But this can’t go on forever—the magnetization M approaches a maximum value, Ms, once all the domains are largely aligned. When M is near this saturation value, further increases in H produce only small additional changes in B. So B climbs quickly at first, then levels off toward a maximum value (the saturation flux density) and rises only slowly as H increases further. That’s why the best description is that B approaches a maximum value and increases slowly.