Correct Answer: A. From general timber
Solution:
Plywood is an engineered wood product made from thin layers or 'plies' of wood veneer that are glued together. While specialty plywoods exist (e.g., marine grade), it is generally manufactured from a wide variety of common timber species, not exclusively from teak or other materials like bamboo or asbestos.
Correct Answer: B. Shisham wood
Solution:
Shisham (Indian Rosewood) is a hard, durable, and fine-textured wood that doesn't warp or split easily, making it an excellent choice for creating detailed and reusable moulds, such as for bricks or decorative elements.
Correct Answer: C. Radial sawing
Solution:
Radial sawing involves cutting boards along the medullary rays, radiating from the center of the log. This method produces very stable, high-quality timber with a straight grain, but it is complex and results in a significant amount of wedge-shaped waste, making it the least economical method in terms of material yield.
Correct Answer: C. Babul
Solution:
Babul (Acacia nilotica) is known for being a very hard, tough, and durable wood, often harder than Teak and Shisham. It is commonly used for tool handles, cart wheels, and other applications requiring high strength and resistance to wear.
Correct Answer: D. Remove sap from the timber
Solution:
Seasoning is the process of drying timber to reduce its moisture content. This primarily involves removing the sap and free water from the wood cells. This process increases strength, stability, and resistance to decay, but its fundamental purpose is moisture (sap) removal.
Correct Answer: C. Thickness
Solution:
Plywood sheets are commercially specified and sold based on their nominal thickness (e.g., 4mm, 6mm, 12mm, 18mm), along with their length and width dimensions. Thickness is the primary specification that determines its strength and suitability for different applications.