7.46. Pick up the correct statement from the following: (a) The capacity of wood to absorb water vapours from air is called hygrocopicity of wood. (b) The uctuation in moisture contents from zero to the bre saturation point cause cracking, warping swetting and shrinkage of wood. (c) At the ber saturation point the timber cell cavities contain no free water (d) All of these are correct. 7.47. The time of seasoning a moderately refractory timber of 25 mm thickness (a) 8 days (b) 10 days (c) 12 days (d) 14 days 7.48. A timber piece having parallel sides thickness less than 50 mm and width exceeding 200 mm is called: (a) A board (b) A batten (c) Baulk (d) None of these 7.49. Pick up the correct denition from the following regarding timbers (a) A timber piece whose breath and thickness do not exceed 50 mm is called a batten (b) The trunk of tree obtained after removing its branches is called a log (c) The timber pieces of parallel sides, having thickness less than 50 mm and width exceeding 50 mm is called a plank. (d) A sound long log of wood having its diameter less than 200 mm is called a pole (e) All of these are correct 7.50. The Indian timbers for obtaining veneers, the thin slides of wood of thickness varying from 0.4 mm to 6 mm is/are: (a) Mahogany (b) Rosewood (c) Sissoo (d) Teak (e) All of these 7.51. The veneers are generally used for making (a) Plywoods (b) Batten boards (c) Laminated boards (d) All of these 7.52.Which one of the following statements regarding the plywoods is correct? (a) Three or more veneers in odd number are glued together with the direction of grains of successive layers at right angles (b) The placing of veneers normal to each other increases both longitudinal and transverses strength (c) While glueing veneers together a pressure 7 to14 kg/ cm2 is applied. (d) All of these are correct. 7.53.Pick up the correct statement from the following: (a) The batten boards are widely used for making partition walls shutters of doors and windows
b) Total thickness of laminate board is about 50 mm (c) The y woods containing more than three plies are designated as multy-ply. (d) All of these are correct 7.54.Pick up the correct statement from the following. (a) The plywoods possess uniform tensile strength in all directions (b) The plywoods are very easy to work and suitable to any design (c) The plywoods are elastic and do not split or crack due to atmospheric changes. (d) The commercial plywoods are available with width up to150 cm and lengths up to 300 cm (e) All of these 7.55.Which one of the following is an impreg timber which is fully or partly covered with resin? (a) Formica (b) Sunglass (c) Sun mica (d) All of these 8. PAINTS 8.1. Pick up the correct statement from the following: (a) Paints are coatings of uid materials which are applied over surfaces of timber and metals. (b) Varnishes are transparent or nearly transparent solutions of resinous materials which are applied over painted surfaces. (c) Distempers are applied over the plastered surfaces. (d) Protective power of paints, varnishes and distempers decreases with time. (e) All of these. 8.2. The base of a paint: (a) is a solid substance in a ne state of division. (b) forms the bulk of paint. (c) determines the character of the paint. (d) imparts durability to the painted surface. (e) All of these. 8.3. Which one of the following is an ingredient of oil borne paint? (a) Base (b) Colouring pigment (c) Vehicle (carrier) (d) Solvent (e) Drier (f) All of these 8.4. White lead (carbonate of lead): (a) forms the base of lead paints. (b) is the most widely used base. (c) is most suitable for wood surfaces. (d) is dense, permanent and water proof. (e) All of these are correct. 8.5. Red lead (oxide of lead): (a) forms the base of lead paints. (b) is used as a primary coat to wood surface. (c) acts as a drier when mixed with linseed oil. (d) All of these.
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