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
41. A first class brick when immersed in cold water for 24 hours should not absorb water more than
a) 15%
b) 20%
c) 22%
d) 25%
Ans: b
42. Crushing strength of a first class brick should not be less than
a) 3.5 N/mm2
b) 7.0 N/mm2
c) 10.5 N/mm2
d) 14.0 N/mm2
Ans: c
43. The main function of alumina in brick earth is
a) to impart plasticity
b) to make the brick durable
c) to prevent shrinkage
d) to make the brick impermeable
Ans: a
44. The percentage of alumina in a good brick earth lies between
a) 5 to 10%
b) 20 to 30%
c) 50 to 60%
d) 70 to 80%
Ans: b
45. Excess of alumina in brick earth makes the brick
a) impermeable
b) brittle and weak
c) to lose cohesion
d) to crack and warp on drying
Ans: d
46. The nominal size of the modular brick is
a) 190 mm x 90mmx 80 mm
b) 190 mm x 190 mm x 90 mm
c) 200 mm x 100 mm x 100 mm
d) 200 mm x 200 mm x 100 mm
Ans: c
47. Percentage of silica in a good brick earth lies between
a) 5 to 10%
b) 20 to 30%
c) 50 to 60%
d) 70 to 80%
Ans: c
48. Excess of silica in brick earth results in
a) cracking and warping of bricks
b) loss of cohesion
c) enhancing the impermeability of bricks
d) none of the above
Ans: b
49. Which of the following ingredients of the brick earth enables the brick to retain its shape ?
a) alumina
b) silica
c) iron
d) magnesia
Ans: b
50. Which of the following pairs gives a correct combination of the useful and harmful constituents respectively of a good brick earth ?
a) lime stone and alumina
b) silica and alkalies
c) alumina and iron
d) alkalies and magnesium
Ans: b