Basic Civil Engineering MCQs - Classification of Timber

1.Which step removes volatiles from the material during firing?
a) Glost firing
b) Single firing
c) Fly firing
d) Bisque firing

Answer: d
Explanation: Tile prepared by dry grinding requires 2 step process. In the first step, tile passes through low temperature firing, called bisque firing.

2. Fluorine emission is a pollutant generated during the manufacturing process.
a) True
b) False

Answer: a
Explanation: Pollutants released are lead, fluorine, waste water, etc. Fluorine emission can be controlled by using scrubbers.

3. Trees are generally classified, based on the mode of growth into:
a) 2
b) 6
c) 4
d) 3

Answer: a
Explanation: The two types are endogenous (inward growth) and exogenous (outward growth).

4. What is the life time of a moderately durable timber?
a) 10-20 years
b) 1-5 years
c) 10-15 years
d) 5-10 years

Answer: d
Explanation: The life time of high durability timber is more than 10 years, for moderately it is between 5-10 years and for low, it is less than 5 years.

5. Which of the following is an example of soft wood?
a) Sal
b) Oak
c) Deodar
d) Mahogany

Answer: c
Explanation: Sal, Oak and Mahogany are all examples of hard wood.

6. Which IS Code gives a classification of commercial timbers and their zonal distribution?
a) IS 620
b) IS 399
c) IS 401
d) IS 190

Answer: b
Explanation: IS 620 gives details about wooden tools handles. IS 401 specifies about the preservation of timber and IS 190 about coniferous sawn timber.

7. IS 3629-1966 classifies timber into 3 classes based on:
a) Availability
b) Average life
c) Durability
d) Density

Answer: b
Explanation: There are 3 classes-class I, class II and class III. Class I timber has an average life of 120 months or more, Class II of 60 months or over, but less than 120 months. Class III has an average life of less than 60 months.

8. Which of the following is a type of non-refractory timber?
a) Semul
b) Teak
c) Sheesham
d) Sal

Answer: a
Explanation: Bases on seasoning, timber has been classified into non-refractory, moderately refractory and eminent refractory timber. Teak and Sheesham are examples of moderately refractory and Sal of eminent refractory timber.

9. Which of the below type of timber has Young’s Modulus greater than 9800 N/mm2, but less than 12600 N/mm2?
a) Average timber
b) Very good timber
c) Good timber
d) Light timber

Answer: c
Explanation: Average timber has Young’s Modulus (E) varying between 6600 N/mm2 and 9800 N/mm2. Very good timber has E greater than 12600 N/mm2. There is no classification as light timber based on E.

10. What is the density of a light timber?
a) 5.5 kN/m3
b) Less than 2.5 kN/m3
c) 2.5 kN/m3
d) Less than 5.5 kN/m3

Answer: d
Explanation: Density of light to very light timber is less than 5.5 kN/m3. Moderate timber has density between 5.5 and 7.5 kN/m3 and heavy to very heavy timber has density greater than 7.5 kN/m3.