Question 104Electricity & Electronics - Assistant Engineer

The correct answer is C) hardwood block. Hardwood blocks are recommended for burnishing the slip rings of an alternator after grinding or turning because they provide a smooth, even surface that can polish the slip rings without causing any damage. The hardness of the wood allows it to compress slightly and conform to the shape of the slip rings, creating a uniform contact surface that helps to restore the desired finish. The other options are not recommended for this task. Canvas wipers (A) may leave fibers or residue on the slip rings, while sandpaper (B) and files (D) are too abrasive and could potentially damage the delicate slip ring surface.