Table 1(i) R and L values for Q1 (Note: Student id: 5730308) Last Digit of Student ID Resistance R (Ohm) Inductance L (H) 0 18 0.08 1 15 0.10 2 10 0.12 3 12 0.15 4 10 0.06 5 20 0.15 6 12 0.10 7 18 0.18 8 14 0.16 9 7 0.12 Table 1(ii) Frequency value for Q1 Last but one digit of Student ID Frequency f (Hz) 0 100 1 120 2 60 3 180 4 120 5 80 6 60 7 50 8 110 9 30 Submission arrangements All coursework must be submitted through Moodle website by 11:55 pm on the specified date Assessment Criteria The work will be assessed by comparison with an approved marking scheme. Fully correct solutions will receive the number of marks indicated. Marks will be reduced for errors in proportion to their severity. You need to indicate the units for all electrical quantities. You need to clearly present the e quations used for calculations and the comparison results. Q1A. Single-Phase AC Circuits A single-phase AC circuit with resistance of R Ohm in series with inductance of L Henry is connected across the supply of 120 V (RMS), f Hertz. The value of R and L are given in Table 1(a) against the last digit of your student ID. The value of frequency f is given in Table 1(b) against the last but one digit of your student ID. (i) Measure & calculate the real power & reactive power supplied by the source and power factor of the circuit. (3 Marks) (ii) Calculate the value of capacitance required, by reactive compensation method, to bring the power factor of the circuit to 0.90. Implement this in the Multisim and measure the power factor. (4 Marks) (Note: Student id: 5730308)Q1B. A single-phase AC circuit with resistance (R) of 8 Ohm in series with inductance (L) and capacitance ( C ) is connected across the supply of 120 V (RMS) with variable frequency. The value of L and C are given in Table 2 against the last digit of your student ID. Calculate i) The resonance frequency & the voltage across the coil & capacitance (3 marks) ii) Simulate the circuit in Multisim and plot VR, VL & VC vs frequency within the frequency ranges: fr 1200 Hz where fr is the resonance frequency. Also explain the simulated graphs with the theoretical values. (5 marks) Table 2: L and C values for Q2 (Note: Student id: 5730308) Last Digit of Student ID Inductance: L (mH) Capacitance: C (µf) 0 12 7 1 10 10 2 15 15 3 20 15 4 8 20 5 25 25 6 20 30 7 10 15 8 12 10 9 15 10 Q2A. Three-phase AC Circuits A balanced star connected load consisting per phase impedance of Z ohm. The value of Z is given in Table 3 against the last digit of your student ID number. The load is connected to a balanced 3-phase supply of 340 V (Line Voltage), 60Hz, star connected, using three-phase 4-wire system. The phase sequence is ABC. In Multisim: (i) Simulate the three-phase circuit and measure the magnitude of line current and phase current. Check your answers by calculation. (3 Marks) (ii) Measure the total real power consumed by the load and power factor of the circuit, using a suitable wattmeter method. Check your answer by a calculation. From the measurements of real power and power factor values, calculate the reactive power flow in the circuit. (3 Marks) (iii) Measure the total real power consumed by the load; if the impedance of the load in phase B is changed to 10-j12Ω (keeping all other load impedance values same as in part (a)). Check your answer by calculation. For this loading condition, determine the reactive power flow in the circuit. (4 Marks)Table 3 Load Impedance (Z) values for Q3 (Note: Student id: 5730308) Last digit of Student ID ZR (Ohm) 0 12-j8 1 12+j14 2 10-j10 3 10+j7 4 15-j8 5 12-j10 6 12+j5 7 15+j12 8 10-j10 9 12+j10 Question 3. (a) What are hysteresis and eddy current losses? Also explains how to minimize the iron losses in the Transformer? (8 Marks) (b) How to identify better magnetic material from the B-H characteristics of several materials? (4 Marks) (c) Briefly explain what information of the core is necessary to solve linear and non-linear magnetic circuit. (3 marks) Important: Your contribution to each answer is important, you must balance view points and data from all independent sources of information i.e. books, journal publications and website (Wikipedia should not be used!!!). In text citation and referencing, all sources including diagrams must be referenced using the CU Harvard system. Q4. Transformer Open & Short Circuit Test IMPORTANT: Student is responsible to collect the data from Lab assistant (Mr. Alex Beaumont) including the physical signature. This information is essential to ensure the originality of your results. If the original signature is not included in this paper the results are considered not valid. Open Circuit Test Data Low-voltage winding voltage (V) Ammeter (A) Wattmeter (W) High-Voltage Winding Voltage (V)Short Circuit Test Data High-voltage winding current (A) Voltage (V) Wattmeter (W) Low-Voltage Winding Current (A) Based on the test results, you need to answer the following questions and prepare the final report. Your report should include any calculations and relevant formula used to answer these questions. 1. Determine the magnetising and working component of the no-load current and draw the equivalent circuit and phase diagram of the open circuit test? (4 Mark) 3. Determine the copper loss of the transformer when it supplies 50% and 70% of full-load. (2 Mark) 4. Determine the efficiency of the transformer at full-load and half-load for 0.85 power factor lagging conditions. (2 Mark) 5. Determine the loading condition at which the efficiency of the transformer would be the maximum? (2 Mark)