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21. Crushing strength of a good building stone should be more than
a) 50 MPa
b) 100 MPa
c) 150 MPa
d) 200 MPa
Ans: b
22. Specific gravity for most of the building stones lies between
a) 1.5 to 2.0
b) 2.0 to 2.5
c) 2.5 to 3.0
d) 3.0 to 3.5
Ans: c
23. Spalling hammer is used for
a) driving wooden headed chisels
b) rough dressing of stones
c) carving of stones
d) breaking small projection of stones
Ans: b
24. Cross cut saw is used for
a) cutting soft stones
b) cutting hard stones
c) cutting large blocks of stones
d) dressing stones
Ans: b
25. Sapwood consists of
a) innermost annular rings around the pith
b) portion of timber between heartwood and cambium layer
c) thin layers below the bark
d) thin fibre which extends from the pith outwards and holds the annular rings together
Ans: b
26. Which of the following trees yields hard wood ?
a) deodar
b) chir
c) shishum
d) pine
Ans: c
27. The radial splits which are wider on the outside of the log and narrower towards the pith are known as
a) heart shakes
b) cupshakes
c) starshakes
d) rindgalls
Ans: c
28. In which of the following pairs both trees yield soft wood?
a) deodar and shishum
b) chir and sal
c) sal and teak
d) chir and deodar
Ans: d
29. Which of the following timbers is suitable for making sports goods ?
a) mulberry
b) mahogany
c) sal
d) deodar
Ans: a
30. Assertion A : Shishum is used for decorative woodwork.
Reason R : Shishum can be polished to an excellent finish.
Select your answer according to the coding system given below :
a) Both A and R are true and R is the correct explanation of A
b) Both A and R are true but R is not the correct explanation of A
c) A is true but R is false
d) A is false but R is true
Ans: a
31. The disease of dry rot in timber is caused by
a) lack of ventilation
b) alternate wet and dry conditions
c) complete submergence in water
d) none of the above
Ans: a
32. Plywood has the advantage of'
a) greater tensile strength in longer direction
b) greater tensile strength in shorter direction
c) same tensile strength in all directions
d) none of the above
Ans: c
33. In which of the following directions, the strength of timber is maximum ?
a) parallel to grains
b) 45° to grains
c) perpendicular to grains
d) same in all directions
Ans: a
34. The moisture content in a well seasoned timber is
a) 4% to 6%
b) 10% to 12%
c) 15% to 20%
d) 100%
Ans: b
35. The trunk of tree left after cutting all the branches is known as
a) log
b) batten
c) plank
d) baulk
Ans: a
36. The age of a tree can be known by examining
a) cambium layer
b) annular rings
c) medullary rays
d) heart wood
Ans: b
37. Plywood is made by bonding together thin layers of wood in such a way that the angle between grains of any layer to grains of adjacent layers is
a) 0°
b) 30°
c) 45°
d) 90°
Ans: d
38. The plywood
a) has good strength along the panel only
b) can be spilt in the plane of the panel
c) has greater impact resistance to blows than ordinary wood
d) cannot be bent more easily than ordinary wood of same thickness
Ans: c
39. The practical limit of moisture content achieved in air drying of timber is
a) 5%
b) 15%
c) 25%
d) 35%
Ans: b
40. First class timber has an average life of
a) less than one year
b) 1 to 5 years
c) 5 to 10 years
d) more than 10 years
Ans: d
