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Difficulty: MediumElectromagnetism and Induction

Inserting a soft iron core into the center of an energized coil of wire increases the overall strength of the magnetic field compared to an air-core coil with the same current and number of turns.

Answer: Answer

Answer

True
The statement is true because soft iron is a ferromagnetic material with high magnetic permeability, which greatly concentrates magnetic flux lines and amplifies the electromagnetic field strength for a given current.

Step-by-Step Solution

1
Identify the factors that determine magnetic flux density in a solenoid
Magnetic flux density is governed by the relation B=μNLIB = \mu \frac{N}{L} I, where μ\mu is core permeability, NN is number of turns, LL is coil length, and II is current.
Core material permeability directly determines the magnetic flux density for a given amount of magnetomotive force.
2
Compare the magnetic properties of soft iron to air
Soft iron is a ferromagnetic substance with relative magnetic permeability hundreds to thousands of times greater than air.
Higher permeability provides a low-reluctance path that concentrates lines of magnetic force inside and around the core.
3
Determine the effect of adding an iron core on overall field strength
Adding the soft iron core significantly amplifies the magnetic field produced by the coil, confirming the statement is true.
This physical principle is the foundation for creating practical electromagnets, relays, and inductors.

Key Concept

Effect of ferromagnetic core permeability on electromagnetic field strength
Estimated Time:45s
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Topics

Electromagnetism and Induction

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