Electrical Science & Circuits 1 Exam Document, CIT 2009/10, Exams of Electrical Engineering

Download Electrical Science & Circuits 1 Exam Document, CIT 2009/10 and more Exams Electrical Engineering in PDF only on Docsity! CORK INSTITUTE OF TECHNOLOGY INSTITIÚID TEICNEOLAÍOCHTA CHORCAÍ Semester 1 Examinations 2009/10 Module Title: Electrical Science and Circuits 1 Module Code: ELTR 6009 School: Electrical & Electronic Engineering Programme Title: Bachelor of Engineering in Electronics – Year 1 Bachelor of Engineering (Honours) in Electronic Systems Engineering – Year 1 Programme Code: EELXE_7_Y1 EELES_8_Y1 External Examiner(s): Dr. A. Donnellan, Dr. P. O’Sullivan Internal Examiner: Mr M. Murray Instructions: Answer question 1 and three other questions Duration: 2 Hours Sitting: Winter 2009 Requirements for this examination: 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. 2 Q1. (a) Briefly describe the structure of an atom and how the valence shell influences atomic properties. [5 marks] (b) Calculate the number of Coulombs of charge and the number of electrons which flow around a circuit if a current of 200mA flows for 4 seconds. (The charge on the electron is 1.6 X 10-19C). [5 marks] (c) Describe the operation of an incandescent bulb, how electrical energy is converted into light energy and comment on the efficiency of the bulb. [5 marks] (d) Calculate the currents (I1, I2 and I3) in each branch of the circuit in Figure 1 and the voltage at the node (Vc). [20 marks] (e) For the circuit shown in Figure 1, describe with the aid of a diagram how the current I1 and the voltage Vc could be measured using a digital multimeter. [5 marks] B1 8V R1 2k R2 4k R4 3k I1 I2 I3 R3 1k Vc B2 4V Figure 1 Q2. (a) Describe ionic, covalent and metallic bonding and outline material properties resulting from each type of bonding. [6 marks] (b) A 12V battery is used to power 2 car headlamps connected in parallel. Each bulb is rated at 55W/12V. Draw a circuit diagram for how these devices would be wired including the light switch in your diagram. Determine the total current drawn from the battery while the lights are switched on, the total power dissipated and the resistance of each bulb. [10 marks] (c) If the 12V battery has a capacity of 64Ah how long can it supply the lamps? [4 marks]