Subtopic: Functional requirements, principles of working, construction and operation of manual, animal, tractor and renewable energy operated equipment for tillage, sowing, planting, fertilizer application, inter-cultivation, spraying, mowing, chaff cutting, harvesting and threshing
Question Statement:
In a combine harvester cleaning shoe, the oscillating chaffer sieve primarily separates:
Options:
(A) Large stones from uncut straw
(B) Grain and small chaff pieces from coarse chaff and unthreshed ear-heads
(C) Weed seeds from fine sand
(D) Grain dust from moisture
Answer Key:
B
Step-by-Step Solution & Explanation
The chaffer sieve is the upper adjustable sieve of the cleaning shoe. The reciprocating motion and upward blast from the cleaning fan allow grains and small chaff to fall through to the cleaning sieve, while floating large chaff, straw fragments, and unthreshed heads off the rear.