Step 1: Understanding the Concept:
The question asks to identify a machine tool that is specifically used to create components with rotational symmetry, such as cylinders, cones (tapers), and spheres. This process involves rotating a workpiece and using a cutting tool to shape it.
Step 2: Detailed Explanation:
Let's analyze the function of each machine listed, assuming they are woodworking machines based on the options:
(A) Band saw: This saw uses a long, continuous band of toothed metal stretched between two or more wheels to cut material. It is excellent for cutting irregular or curved shapes, but it cannot produce rotationally symmetric components like cylinders or spheres.
(B) Circular saw (or Table saw): This saw uses a circular toothed blade to make straight cuts. Its primary function is ripping (cutting along the grain) and cross-cutting (cutting across the grain). It is not used for producing round components.
(C) Wood planer (or Thicknesser): This machine is used to make the faces of a board flat and parallel to each other, and to reduce it to a consistent thickness. It produces flat surfaces, not round ones.
(D) Wood turning lathe: A lathe is a machine tool that rotates a workpiece about an axis of rotation to perform various operations such as cutting, sanding, knurling, drilling, or turning. The workpiece (e.g., a piece of wood) is held and rotated by the lathe, while a stationary cutting tool is advanced against it. This action is called "turning." By moving the cutting tool parallel to the axis of rotation, a cylinder is formed. By moving it at an angle, a cone (taper) is formed. By using special tools and techniques, spherical and other complex curved profiles can be created. The lathe is the quintessential machine for producing any component with rotational symmetry.
Step 3: Final Answer:
The wood turning lathe is the machine used to produce cylindrical, conical, and spherical components by rotating a workpiece against a cutting tool. Therefore, option (D) is the correct answer.