Exam: Electrical Science & Circuits 1, BEng in Electronic Engineering - CIT, 2011/12, Exams of Electrical Engineering

Download Exam: Electrical Science & Circuits 1, BEng in Electronic Engineering - CIT, 2011/12 and more Exams Electrical Engineering in PDF only on Docsity! Page 1 of 3 CORK INSTITUTE OF TECHNOLOGY INSTITIÚID TEICNEOLAÍOCHTA CHORCAÍ Semester 2 Examinations 2011/12 Module Title: Electrical Science and Circuits 2 Module Code: ELTR6010 School: Mechanical, Electrical & Process Engineering Programme Title: Bachelor of Engineering in Electronic Engineering – Year 1 Programme Code: EELXE_7_Y1 External Examiner(s): Dr Andrew Donnellan, Mr Ian Kennedy Internal Examiner(s): Mr Michael Murray Instructions: Answer QUESTION ONE and TWO other questions Duration: 2 hours Sitting: Autumn 2012 Requirements for this examination: Note to Candidates: Please check the Programme Title and the Module Title to ensure that you have received the correct examination paper. If in doubt please contact an Invigilator. Page 2 of 3 Q1. (a) Explain, with the aid of diagrams, the terms phase delay and power factor in relation to AC circuits. [6 marks] (b) If the measured power factor of an RC circuit, connected to 230V/50Hz AC supply, is 0.5, determine the phase angle and time delay between the measured voltage and current. If the resistor value is 180Ω, determine the value of the capacitor. [12 marks] (c) For the circuit shown in Figure 1, determine: i. The impedance of the circuit ii. The current flowing in the circuit iii. The phase angle of the current relative to voltage iv. The power dissipated in the circuit. [22 marks] Figure 1 Q2. (a) Describe and illustrate how an electromagnet could be built and outline the parameters which determine the magnetic field of an electomagnet. [6 marks] (b) A DC permanent magnet motor having a coil of length 10cm with 5000 turns is to exert a maximum rotation force of 1N. If the magnetic flux is 2mT, estimate the current which must flow in the coil. [12 marks] (c) Describe with the aid of a diagram, the construction and operation of a transformer. Give some examples of transformer applications. [12 marks]