Step 1: Understanding the equipment and methods.
- Hammer mill (P): Operates using high-speed impact to break down materials, hence the method is Impact.
- Burr mill (Q): Uses grinding action between two rotating plates, making it an Attrition process.
- Crushing rolls (R): Uses compression to reduce the size of material, hence the method is Compression.
- Rotary knife (S): Uses cutting to reduce the size of materials, hence the method is Cutting.
Step 2: Analyzing the options.
- (A) Incorrect, because the method of operation for Crushing rolls is compression, not impact.
- (B) Incorrect, as it incorrectly matches the method for Hammer mill and Burr mill.
- (C) Incorrect, the method for Burr mill should be Attrition, not Impact.
- (D) Correct, this correctly matches each equipment with its corresponding method of operation.
Step 3: Conclusion.
The correct answer is (D) P-(3), Q-(4), R-(1), S-(1).
