Bce0103:Building Science Question Paper
Bce0103:Building Science
Course:Diploma In Civil Engineering
Institution: Meru University Of Science And Technology question papers
Exam Year:2011
QUESTION ONE – (30 MARKS)
(a) Building environment is an important consideration in any given design. Explain.
(2 Marks)
(b) Define the following terms:
(i) Thermal comfort (2 Marks)
(ii) Indoor climate (2 Marks)
(c) Briefly elaborate any 3 physical variables that affect the Thermal comfort in a given
building. (6 Marks)
(d) Elaborate 3 main functions of artificial lighting (6 Marks)
(e) (i) Define the term “daylight factor” (2 Marks)
(ii) A minimum daylight factor of 4 percent is required at a certain point inside a room.
Calculate the natural illuminance that this represents assuming that an unobstructed
standard sky gives an illuminance of 5000lx (4 Marks)
(f) Differentiate between airborne sound and impact sound. (4 Marks)
(g) A particular sound wave has a frequency of 440Hz and a velocity of 340 m/s. Calculate
the wavelength of this sound. (2 Marks)
2
SECTION B
QUESTION TWO – (15 MARKS)
(a) With an aid of a well labeled diagram explain the “green house effect” in buildings.
(6 Marks)
(b) State three benefits of thermal insulation in buildings. (3 Marks)
(c) Differentiate between thermal conductivity and thermal conductance of a material.
(4 Marks)
(d) State 2 factors affecting thermal conductivity of a material. (2 Marks)
QUESTION THREE – (15 MARKS)
(a) Define the term “U” value stating its SI units. (2 Marks)
(b) Define thermal resistance and state 3 types of thermal resistances in a given building.
(4 Marks)
(c) A domestic pitched roof of tiles on felt sacking with a plasterboard ceiling has an existing
u-value of 1.9w/m2k. Calculate the minimum thickness of fibre glass insulation in the
roof space required to give the roof a new u-value of 0.25w/m2k. The thermal
conductivity of the fibre glass used is 0.04w/mk (5 Marks)
(d) A block wall measures 5m x 2.8m in overall length and height. The wall contains one
window 14000mm x 800mm and one door 1900mm x 750mm. The u-values in w/m2k
are: Block work 0.58, windows 5.6 and doors 3.4. Calculate the average u-value of this
wall. (4 Marks)
QUESTION FOUR – (15 MARKS)
(a) Define the following terms stating their S.I units:
(i) Luminous intensity (2 Marks)
(ii) Luminous flux (2 Marks)
(b) A small source of light has a mean spherical intensity of 300cd. One quarter of the total
flux emitted from the source fall at right angles onto a surface measuring 4m x 0.8m.
Calculate:
(i) The total luminous flux given out by the source. (2 Marks)
(ii) The illuminance produced on the surface (2 Marks)
(c) State the inverse square law of illumination (2 Marks)
(d) Differentiate between disability glare and discomfort glare. (4 Marks)
QUESTION FIVE – (15 MARKS)
(a) Define the following terms in relation to sound:
(i) Wavelength (1 Mark)
(ii) Frequency (1 Mark)
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(iii)Velocity (1 Mark)
(iv) Pitch (1 Mark)
(b) State Sabine?s method of calculating reverberation times in rooms. (2 Marks)
(c) Define the term „decibel? (1 Mark)
(d) What do you understand by the term „threshhold of pain? (2 Marks)
(e) A sound has a pressure of 4.5 x 10-2 pa when measured under certain conditions.
Calculate the sound pressure level of the sound. Threshold hearing pressure
= 20 x 106 pa (4 Marks)
(f) Name any 2 absorbers of sound. (2 Marks
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