Question

The surface area of the face of a 3-D element is a _____________

(a) 3-D tensor

(b) 2-D tensor

(c) Scalar

(d) Vector

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Asked question is from The Geometry of FVM Elements topic in chapter Finite Volume Methods of Computational Fluid Dynamics

Answer 1

Correct choice is (d) Vector

To explain: The surface area of the face of a 3-D element is a vector with the area as its magnitude and pointing in a direction. This direction decides if the face points outwards or inwards. Moreover, the area is the result of the cross product of two vectors which will again be a vector.