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JSS3: BASIC TECHNOLOGY - 1ST TERM

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  1. Materials & Processing - Timber I | Week 1
    6 Topics
    |
    1 Quiz
  2. Materials & Processing - Timber II | Week 2
    4 Topics
    |
    1 Quiz
  3. Processing of Materials - Metals | Week 3
    5 Topics
    |
    1 Quiz
  4. Processing of Clay, Ceramics and Glass | Week 4
    5 Topics
    |
    1 Quiz
  5. Methods of Producing Plastics & Rubber | Week 5
    2 Topics
    |
    1 Quiz
  6. Drawing Practice - Isometric Drawing | Week 6
    4 Topics
    |
    1 Quiz
  7. Oblique Projection | Week 7
    2 Topics
    |
    1 Quiz
  8. Orthographic Projection | Week 8
    4 Topics
    |
    1 Quiz
  9. Perspective Drawing (One - Point Perspective Drawing) | Week 9
    4 Topics
    |
    1 Quiz

Quizzes

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Content:

  • Theory Questions & Answers
    • We have provided answers to the questions, try to attempt the questions yourself without checking the answers.
    • Click on the “View Answers” button to view the answers.

Evaluation Questions:

1. (a) What is wood seasoning?

(b) Name two methods of wood seasoning.

(c) Name three (3) reasons for seasoning wood.

(d) If a sample of wood weighs 136 gm before and 100 gm after drying, what is the percentage moisture content?

2. (a) What are timber defects?

(b) Name two categories of timber defects.

(c) Give two examples of defects that fall under each category.

3. (a) What is timber preservation?

(b) State five (5) properties of good timber preservatives.

(c) List three methods of applying preservatives.

View Answers

Theory Questions – Timber II

  1. (a) What is wood seasoning?

Answer: The process of reducing the moisture or water content of wood is called wood seasoning.  

 

(b) Name two methods of wood seasoning.

Answer:

  • Natural or Air Seasoning

  • Artificial or Kiln Drying

 

 (c) Name three (3) reasons for seasoning wood.

Answer:

1. Seasoning makes the wood stronger.

2. It makes the wood lighter in weight.

3. It makes wood take in (absorb) preservatives easily.

 

 (d) If a sample of wood weighs 136 gm before and 100 gm after drying, what is the percentage moisture content?

Solution:

⇒ \( \frac{wet \: weight \: – \: dry \: weight}{wet \: weight} \: \times \: \frac{100}{1} \)

⇒ \( \frac{136gm \:  – \:  100gm}{136gm} \: \times \: \frac{100}{1} \)

= \( \frac{36}{136} \: \times \: \frac{100}{1} \)

= \( \scriptsize 0.264 \: \times \: 100\) = \( \scriptsize 26.4 \% \)  

 

2. (a) What are timber defects?

Answer: Timber defects are faults or irregularities in wood, caused either naturally or during the processing of the wood, which reduces the value or quality of the timber.

 

(b) Name two categories of timber defects.

Answer: Defects in timber can be Natural or Artificial.

 

(c) Give two examples of defects that fall under each category.

Answer: Natural – Knots, Shakes Artificial – Bow, Cup  

 

3. (a) What is timber preservation?

Answer: Wood preservation is the process of applying chemicals to wood, so as to make it poisonous to insects, worms, and fungi, and to prolong its lifespan. The solutions used for this purpose are referred to as preservatives.  

 

(b) State five (5) properties of good timber preservatives.

Answer:

i) They must be toxic to fungi, pests and marine organisms.

ii) They should not have corrosive properties.

iii) It should not contain any harmful substances, gases etc.

iv) It should not have an unpleasant smell.

v) It should not affect timber strength.

 

(c) List three methods of applying preservatives.

Answer:

  • Cold Immersion
  • Spraying
  • Brushing

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