Exam Questions - Electrical Circuits Laboratory - Spring 2005 | EE 224, Lab Reports of Electrical and Electronics Engineering

Download Exam Questions - Electrical Circuits Laboratory - Spring 2005 | EE 224 and more Lab Reports Electrical and Electronics Engineering in PDF only on Docsity! West Virginia University Lane Department of Computer Science and Electrical Engineering EE 224 - Electrical Circuits Laboratory Tuesday, April 19, 2005 Exam - Spring 2005 Section 1 2 parts , 50 points, 60 minutes One page A4 size equation sheet and calculator allowed Show all your work. Good Luck ! Name: 1 Part I: (2 points each) 1. For the circuit shown below, write the expression for θ (phase difference between the applied voltage and current flowing through the circuit) in terms of ω, C andR AC R Vm cos (wt) Im cos (wt + 0) C Figure 1: Series RC circuit Ans: 2. Which of the following is true ? (a)In an inductor, current lags the applied voltage by 90o. (b)In an inductor, current leads the applied voltage by 90o. (c)In an inductor, current lags or leads the applied voltage by 90o depending upon the input frequency. AC R L Vm cos (wt) Im cos (wt - 0) Figure 2: Series RL circuit 3. For the series RL circuit shown in Fig.2, write down the expression for apparent power delivered by the source. Ans: 2 Q2: The apparent power in a reactive circuit is 5 units and the average power is 3 units. Find the reactive power and the power factor. 5 Q3: Design a circuit that will produce underdamped oscillations given the following specifi- cations for the signal. The damping factor should be between 10 s−1 and 100 s−1. L = 10 H. Hint : α = R 2L , ωo = 1√ LC 6