Vector calculus property: The gradient of any scalar field always yields which type of vector field?

Introduction / Context:
In vector calculus, the gradient operator (∇) applied to a scalar field produces a vector field. Recognizing the properties of this gradient field is crucial in electromagnetics, fluid mechanics, and physics.

Given Data / Assumptions:

• We start with a scalar field φ(x, y, z).
• Gradient definition: ∇φ = (∂φ/∂x) i + (∂φ/∂y) j + (∂φ/∂z) k.
• No additional constraints on φ.

Concept / Approach:

The gradient of a scalar field defines a conservative field. By definition, conservative vector fields can be written as the gradient of a scalar potential. A conservative field is also irrotational because curl(∇φ) = 0 always holds (identity of vector calculus).

Step-by-Step Solution:

Verification / Alternative check:

In electrostatics, the electric field E = −∇V is both conservative and irrotational, derived from scalar potential V. This confirms the gradient field's nature.

Why Other Options Are Wrong:

• Solenoidal field: requires ∇·F = 0, which is not guaranteed by a gradient field.
• Irrotational is true, but the canonical name is conservative.
• None: incorrect because gradient always defines a conservative field.

Common Pitfalls:

• Confusing solenoidal (divergence-free) with conservative (gradient of a scalar).
• Overlooking that while gradients are always irrotational, they are defined as conservative fields.

Final Answer:

A conservative field