Is a cube a gaussian surface?

Hint: We are asked if a particular shape is a gaussian surface. In order to answer this, we initially have to define a gaussian surface and provide conditions (if any). After defining a gaussian surface we see if the definition and the conditions match that of the cube. If the conditions match that of a cube, then the cube is a gaussian surface.

Complete answer:
Let us start by defining a gaussian surface. A Gaussian surface is usually a shape or a closed surface in the three-dimensional space through which the flux of a vector is calculated, usually gravitational field, magnetic field or an electric field.
Now that we have defined a gaussian surface, we take a look at the shape or the surface given to us. The surface given is a cube. A cube is a surface that is closed; hence it can be a gaussian surface. The cube is also a three-dimensional shape. You can put charges in a cube and apply the gauss law to find the flux. The gauss law is true for any closed shape, be it a sphere, cuboid, cube or any other closed surface. For finding the electric flux of the given charge, the charge needs to be distributed uniformly (uniform charge distribution).
Yes, a cube is a gaussian surface.

Note: The gaussian surface is an imaginary shape or surface in the three-dimensional space that helps us in calculating the flux of a vector. Consideration of the gaussian surface helps us find the electric flux of a uniform charge distribution.