Separation of substances Worksheet-8

Separation of substances Worksheet-8


Multiple-Choice Question:

  1. Which kind of threshing is done by holding a pile of crop and beating on a rock?

(A) Pedal threshing                         (B) Manual threshing

(C) Machine threshing


  1. What are the steps involved from cutting of rice crop to its safe storage?

(A) Cutting –> storing –> threshing –> drying –> storage

(B) Cutting  –> threshing –> drying, cleaning –> storage

(C) Cutting –> threshing –> cleaning –> drying –> storage


  1. What does a combine harvester do?

(A) It combines cutting, threshing, cleaning and stores grain in a bin in one operation

(B) It is a fast threshing machine 

(C) It dries the paddy


  1. The liquid above the sediment/s is/are called _____.

(A) supernatant  (B) sediments      (C) solution


  1. How long do you leave the cut crop in the field?

(A) Until it reaches the desired moisture level

(B) Until it is dry

(C)  As long as needed 


  1. Why is threshing at the correct time important?

(A) To loosen and separate the husk from the grain

(B) To minimize losses because of deterioration and shattering of grain 

(C) Both of these


  1. What is not a threshing method?

(A) Foot trampling (walking over)           (B) Pedal thresher

(C) Winnowing


  1. What is cleaning?

(A) Cleaning the thresher after use

(B) Removing moisture

(C) Removing dirt, chaff, straw from the grains 


  1. Why is cleaning important?

(A) It removes unwanted materials from the grain

(B)  It is not important

(C)  To improve the milling process


  1. The solid particle/s that settles down during sedimentation is/are called _____.

(A) supernatant  (B) sediments      (C) solution


Answer Key:

  1. (B)
  2. (C)
  3. (B)
  4. (B)
  5. (A)
  6. (B)
  7. (C)
  8. (C)
  9. (A)
  10. (B)