Introduction:
Streamlines and equipotential lines are commonly used in fluid mechanics to visualize the flow pattern and potential distribution in a fluid field. The pattern of these lines varies depending on the type of flow, whether it is a source flow or a sink flow. In this context, the statement claims that the pattern for streamlines and equipotential lines is different for source and sink flow.

Explanation:
To understand why the statement is true, let's first define what source flow and sink flow are:

- Source Flow: In source flow, fluid is flowing outward from a central point, creating a radial flow pattern. It can be visualized as a fluid source that emits fluid particles in all directions.
- Sink Flow: In sink flow, fluid is flowing inward towards a central point, creating a converging flow pattern. It can be visualized as a fluid sink that absorbs fluid particles from all directions.

Now, let's analyze the pattern of streamlines and equipotential lines for each type of flow:

1. Source Flow:
- Streamlines: In source flow, the streamlines are radial lines that originate from the central point and spread outwards. The streamlines are equidistant from each other, indicating a uniform flow rate at every point along the streamlines.
- Equipotential Lines: The equipotential lines in source flow are concentric circles centered at the source point. These lines represent the potential distribution in the flow field. The equipotential lines are perpendicular to the streamlines, indicating that the potential gradient is perpendicular to the flow direction.

2. Sink Flow:
- Streamlines: In sink flow, the streamlines are converging lines that approach the central point. The streamlines become closer to each other as they approach the sink, indicating an increasing flow rate towards the center.
- Equipotential Lines: The equipotential lines in sink flow are also concentric circles centered at the sink point. Similar to source flow, the equipotential lines are perpendicular to the streamlines, indicating the potential gradient direction.

Conclusion:
In conclusion, the pattern for streamlines and equipotential lines is different for source and sink flow. Source flow exhibits radial streamlines and concentric equipotential lines, while sink flow exhibits converging streamlines and concentric equipotential lines. Understanding these patterns is crucial for visualizing and analyzing fluid flow in different scenarios.