The magnetic field formed by magnetic lines of force is called what?

• A. Flux field
• B. Magnetic field
• C. Electric field
• D. Magnetic flux

Answer: (A)

The concept being tested is distinguishing between the magnetic field itself and the quantity called magnetic flux. Magnetic lines of force visualize the magnetic field, which is a vector field (often denoted B) that describes both the strength and direction of the magnetic influence at every point in space. The field is what those lines represent.

Magnetic flux, on the other hand, is a separate quantity: it measures how much of that field passes through a given surface. It’s a scalar value given by Φ_B = ∫ B · dA, with units of Weber. So while flux depends on the field, it is not the field itself.

Therefore, the term that names the field depicted by the lines of force is the magnetic field (often called the B-field or magnetic flux density). Magnetic flux is a related but distinct concept.