Electric flux density, also known as electric field intensity or electric displacement, is a measure of the strength of an electric field. It is defined as the amount of electric flux passing through a unit area perpendicular to the direction of the electric field.

To calculate the electric flux density, we can use the formula:

Electric Flux Density (D) = Charge (Q) / Area (A)

Given:
Charge (Q) = 16 C
Area (A) = 4 m^2

Let's calculate the electric flux density using the given values:

1. Determine the Charge (Q):
Q = 16 C

2. Determine the Area (A):
A = 4 m^2

3. Calculate the Electric Flux Density (D):
D = Q / A
D = 16 C / 4 m^2
D = 4 C/m^2

Therefore, the electric flux density is 4 C/m^2.

In summary:
- Charge (Q) is the amount of electric charge in the conductor, given as 16 C.
- Area (A) is the cross-sectional area perpendicular to the direction of the electric field, given as 4 m^2.
- Electric Flux Density (D) is the strength of the electric field, calculated as Q/A.
- By substituting the given values into the formula, we find that the electric flux density is 4 C/m^2.

Note: Electric flux density is a vector quantity, meaning it has both magnitude and direction. In this case, since only the magnitude is given, we assume the direction is implied to be normal to the area.