Download Civil Engineering Exam Materials: Engineering Science Module, CCIVL 6009, Winter 2010 and more Exams Engineering Science and Technology in PDF only on Docsity! Page 1 of 7 CORK INSTITUTE OF TECHNOLOGY INSTITIÚID TEICNEOLAÍOCHTA CHORCAÍ Semester 1 Examinations 2010/2011 School: School of Engineering Programme Title: Bachelor of Engineering in Civil Engineering Programme Code: CCIVIL_7_Y1, CCIVE_6_Y1 Module Title: Engineering Science Module Code: CCIVL 6009 External Examiner(s): Mr. J. Murphy, Ms. M. Kyne Internal Examiner(s): Mary Quirke Instructions: Question 1 is compulsory, all candidates must attempt question 1. Answer THREE other questions. Each question carries 25%. Duration: 2 hours Sitting: Winter 2010 Requirements for this examination: Log tables are to be made available to students Note to Candidates: Please check the Programme Title and the Module Title to ensure that you are attempting the correct examination. If in doubt please contact an Invigilator. Page 2 of 7 Q.1 Compulsory. (a) Describe the two types of hearing loss that can be caused by exposure to noise. (4 marks) (b) A sound has an intensity of 3.16 x 10 -4 W/m 2 . Calculate the sound intensity level in decibels if the threshold of hearing reference intensity is 1 x 10 -12 W/m 2 . (4 marks) (c) Explain each of the following terms with reference to the thermal properties of building materials: (i) Thermal conductivity (ii) Thermal resistance (iii)Thermal transmittance (2 marks) (2marks) (2 marks) (d) Explain the method(s) of heat transfer that are considered for calculating thermal transmittance. (2 marks) (e) Compare the luminous efficacy, nominal life and colour rendering of 3 different lamp types, stating suitable applications for each. (9 marks) Page 5 of 7 Q.4(a) (i) Identify 4 different types of thermal insulation material and suggest how they are used in buildings. (ii) How do these thermal insulation materials reduce heat transfer between areas? (5 marks) (2 marks) (b) Calculate the U value of a cavity wall with a 103 mm brick outer leaf, 50 mm of clear cavity, 40 mm of insulation board, then a 115 mm high performance aerated concrete block inner leaf with a 15 mm layer of light weight plaster. Values of thermal conductivity in W/m K are: lightweight plaster 0.18, aerated concrete blockwork 0.11, insulation board 0.025, brickwork 0.77. Standard thermal resistances in m 2 K/W are : internal surface 0.12, external surface 0.06, cavity 0.18. (9 marks) (c) Explain the term thermal bridge and give 2 examples. (4 marks) (d) (i) Determine the rate of heat loss through a 4 m2 portion of a brick wall 15 cm thick if the inside temperature is 20 o C and the outside temperature is 0 o C. The thermal conductivity of the brick is 0.63 W/m.K. (ii) How much heat will be lost through the same wall in one hour? (4 marks) (1 marks) Page 6 of 7 Q5. (a) Calculate the actual reverberation time for a hall with a volume of 5000 m 3 , given the following data for a frequency of 500 Hz. Surface Surface area m 2 Absorption coefficient Brickwork 500 0.03 Plaster on solid 600 0.2 Acoustic board 100 0.7 Carpet 300 0.3 Curtain 70 0.4 seats 400 seats 0.3 units each (9 marks) (b) If the optimum reverberation time for the above hall is 1.5 s then calculate the number of extra absorption units needed. (4 marks) (c) Why would it be desirable to change the reverberation time to 1.5 sec? (2 marks) (d) (i) State the inverse square law of illumination. (i) A light has a luminous intensity of 1200 cd and acts as a point source. Calculate the illuminance produced on surfaces at the following positions (a) At 2 m distance from the lamp (b) At 6 m distance from the lamp (3 marks) (3 marks) (e) Give a brief account of four principles for passive solar design. (4 marks) Page 7 of 7 Useful formula: l TTkA t Q )( 12 Power = U A T TLl 0 o I I I SILL log10 oP P SPLLp log20 Q = mc T Useful constants : I0 = 10 -12 W/m 2 and Po= 2x10 -5 N/m 2 S V RT 16.0 60 Sabine’s formula
