Bar Magnet vs Electromagnet
Comparison
Property
Magnetic Field Source
Can Turn Off?
Bar Magnet
Natural/permanent
magnetism
No — always on
Field Strength
Fixed
Polarity Reversible?
No
Field Shape
Used in Transformer?
Dipole (north and south
poles)
No
Direction of Field
Fixed (north to south)
Electromagnet
Electric current through a
coil
Yes — only active when
current is flowing
Variable — depends on
current and coil turns
Yes — by reversing current
direction
Similar dipole pattern
Yes — core component of
transformers
Changes with AC current