Civil engineer objective questions – Building Materials (Section-5)

 1. Plywood is identified by

a ) volume

b ) weight

c ) thickness

d ) area

2. Plywood is obtained by gluing wooden sheets at a specification of

a ) 100 to 150 N / cm²

b ) both ( a ) and ( b ) of above

c) 100 degree to 130 degree celcius

d) none of above

3. Plywood is generally available

a ) 1 mm thick

b ) 2 mm thick

c) 3 to 4 mm thick

4. Which of the following is not hardwood?

a ) deodar

b ) sal

c ) teak

d ) oak

5. Which of the following is not a soft wood ?

a ) deodar

 b ) walnut

c ) shisham

d ) kail

6. When the timber is attacked by fungus and reduced to powder , it is called

a ) wet rot

b ) dry rot

c ) druxiness

d ) dottiness

7. Based on its dry weight , a freshly felled free may contain water

a ) 25 %

b ) 50 %

c ) 75 %

d ) 100 %

8. The time require for the seasoning of timber in air is about water

a ) 1 to 2 months

b ) 2 to 4 months

c ) 4 to 6 months

d ) 6 to 9 months

9. In the manufacture of plywoods the veneers are placed such that the grains of one layer are

a ) at 45 ° with the grains of the other

b ) at right angles with the grains of the other

c ) at 60 ° with the grains of the other

 d ) parallel to the grains of the other

10. In dry rot , wooden material defect caused due to

a ) ant

b ) fungus

c ) weather

d ) none of the above

11. Which of the following wood has the maximum resistance to white ants ?

a ) deodar

b ) sal

c ) walnut

d ) teak

12. Creosote oil is used to preserve the wood from ,

a ) rot and white ant

b ) fire hazards

c ) cracking

d ) none of the above

13

13. Knots in timber are

a ) defects caused by crushing fibers

b ) splits radiating from the centre

c ) speckled strains

d ) signs of branches cut off

14. The defect caused by the shrinkage of timber is

a ) crook

b ) cup and bow

c ) twist

d ) none of the above

15. Impregnating of timber is done to increase

a ) fire resistance of timber

b ) seasoning of timber

c ) weight of timber

d ) none of the above

16. Timber can be made reasonably fire resistant

a ) by soaking it in ammonium sulphate

b ) by applying tar paint

c ) by pumping creosote oil into timber under high pressure

d ) none of the above

17. The main purpose of seasoning is

a ) to make the timber fire resistant

b ) to remove the moisture from the timber at uniform rate

c ) to make the timber water proof

d ) none of the above

18. Which one is false ?

a ) seasoning is done to control moisture

b ) sal wood is used for ornamental purpose

c ) sap is suck in spring by roots of the tree

d ) all of the above

19. The seasoning of timber

a ) makes the timber light , strong and stable

b ) prevents warping , cracking and shrinkage in timber

 c ) makes timber resistant to decay by fungi , termites etc. and also resistant to electricity

d ) all of the above

20. The number of veneers glued under pressure in a plywood must be

a ) prime number

c ) even number

d ) odd number

21. The curved swellings from the growth of layers or wounds left after branches are cut off in an irregular manners , are known as

a ) knots

b ) composite number

c ) burls

d ) none of the above

22. The defects in wood due to hardening is

a ) knots

b ) rind galls

c ) burls

d ) all of the above

23. Which of the following statements is not correct ?

a ) kiln seasoned timber is stronger than natural seasoned timber

b ) moisture content in the timber can be reduced to any desired level in kiln seasoning

c ) kiln seasoning is quicker than natural seasoning

d ) kiln seasoning requires less stacking space but more expensive than the natural seasoning

24. In a well – seasoned timber , the moisture content will be in the range of

a ) 20-25 %

c ) 10-12 %

b ) 15-20 %

d ) 5-7 %

25. Most economical methods of sawing wood is

a ) radial sawing

c ) quarter sawing

b ) tangential sawing

 d ) flat sawing

26. A thin sheet of wood sliced from a log of wood is called

a ) plywood

b ) laminated board

c ) veneer

d ) none of the above