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Unformatted text preview: gilbert (amg3448) HW08 tsoi (57210) 1 This printout should have 24 questions. Multiplechoice questions may continue on the next column or page find all choices before answering. 001 (part 1 of 5) 10.0 points In a series RLC AC circuit, the resistance is 30 . 6 , the inductance is 33 . 6 mH, and the capacitance is 7 . 22 F. The maximum potential is 139 V, and the angular frequency is 636 . 62 rad / s. Calculate the maximum current in the cir cuit. Correct answer: 0 . 700098 A. Explanation: Let : = 636 . 62 rad / s , C = 7 . 22 F = 7 . 22 10 6 F , L = 33 . 6 mH = 0 . 0336 H , R = 30 . 6 , and V max = 139 V . The capacitive reactance is X C = 1 C = 1 (636 . 62 rad / s) (7 . 22 10 6 F) = 217 . 562 , and the inductive reactance is X L = L = (636 . 62 rad / s) (0 . 0336 H) = 21 . 3904 . The maximum current is I max = V max Z = V max R 2 + ( X L X C ) 2 = 139 V (30 . 6 ) 2 + (21 . 3904  217 . 562 ) 2 = . 700098 A . 002 (part 2 of 5) 10.0 points Determine the maximum voltage across the resistor. Correct answer: 21 . 423 V. Explanation: The maximum voltage across the resistor is V R = I max R = (0 . 700098 A) (30 . 6 ) = 21 . 423 V . 003 (part 3 of 5) 10.0 points Determine the maximum voltage across the inductor. Correct answer: 14 . 9754 V. Explanation: The maximum voltage across the inductor is V L = I max X L = (0 . 700098 A) (21 . 3904 ) = 14 . 9754 V . 004 (part 4 of 5) 10.0 points Determine the maximum voltage across the capacitor. Correct answer: 152 . 315 V. Explanation: The maximum voltage across the capacitor is V C = I max X C = (0 . 700098 A) (217 . 562 ) = 152 . 315 V . 005 (part 5 of 5) 10.0 points What is the power factor for the circuit? Correct answer: 0 . 154122. Explanation: gilbert (amg3448) HW08 tsoi (57210) 2 The phase angle between the voltage and the current in the circuit is = tan 1 X L X C R . Since X L X C R = 21 . 3904  217 . 562 30 . 6 = 6 . 41083 , the power factor is cos = cos tan 1 X L X C R = cos tan 1 ( 6 . 41083) = . 154122 . 006 (part 1 of 2) 10.0 points A resistance R and a 1 . 2 H inductance are in series across a 60 Hz AC voltage. The voltage across the resistor is 25 V and the voltage across the inductor is 45 V. What is the resistance R ? Correct answer: 251 . 327 . Explanation: Let : L = 1 . 2 H , f = 60 Hz , V R = 25 V , and V L = 45 V . The potential difference across an inductor is V L = I X L = I 2 f L and the potential difference across a resistor is V R = I R . Thus we have V R V L = I R I 2 f L = R 2 f L , so the resistance is R = V R V L 2 f L = 25 V 45 V 2 (60 Hz) (1 . 2 H) = 251 . 327 . 007 (part 2 of 2) 10.0 points What is the AC input voltage?...
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This note was uploaded on 03/22/2012 for the course PHYS 302L taught by Professor Tsoi during the Spring '10 term at University of Texas at Austin.
 Spring '10
 TSOI
 Physics, Resistance

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