A fluid flow is represented by the velocity field $$\overrightarrow V = ax\,\overrightarrow i + ay\,\overrightarrow j ,$$ where a constant . The equation of stream line passing through a point $$(1, 2)$$ is

In a flow field, the streamlines and equipotential lines

Existence of velocity potential implies that

Streamlines, path lines and streak lines are virtually identical for