The softness or hardness of a grinding wheel depends upon the type & amount of bonding material used. For general purpose cutter grinding __________ grinding wheel is normally used.

ANS:D - aluminium oxide

For general-purpose cutter grinding, an aluminium oxide grinding wheel is commonly used. Here's why:

1. Hardness: Aluminium oxide is a hard material, making it suitable for grinding applications where a harder wheel is needed to maintain shape and cutting efficiency over time.
2. Versatility: Aluminium oxide grinding wheels are versatile and can be used for a variety of materials, including steel, iron, and other metals. This makes them suitable for general-purpose cutter grinding where a range of materials may need to be worked on.
3. Abrasive Properties: Aluminium oxide has excellent abrasive properties, allowing it to efficiently grind away material from the workpiece, resulting in precise and effective cutting.
4. Durability: These grinding wheels tend to be durable, with good resistance to wear and abrasion, which is important for extended use in industrial applications.