hw 30 - nguyen (jmn727) – homework 30 – Turner –...

This preview shows pages 1–2. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: nguyen (jmn727) – homework 30 – Turner – (59070) 1 This print-out should have 12 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 10.0 points Consider a series RLC circuit. The applied voltage has a maximum value of 110 V and oscillates at a frequency of 83 Hz. The circuit contains a capacitor whose capacitance can be varied, a 1200 Ω resistor, and a 2 . 9 H inductor. Determine the value of the capacitor such that the voltage across the capacitor is out of phase with the applied voltage by 37 ◦ , with V L leading V max . Correct answer: 0 . 617598 μ F. Explanation: The phase relationships for the voltage drops across the elements in the circuit are shown in the figure. V R V L V C V m a x φ α Let : α = 37 ◦ , f = 83 Hz , L = 2 . 9 H , R = 1200 Ω . From the figure, the phase angle is φ = 90 ◦- α = 90 ◦- 37 ◦ = 53 ◦ , since the phasors representing I max and V R are in the same direction (in phase). The angular frequency is ω = 2 π f = 2 π (83 Hz) = 521 . 504 Hz . We know that X L = ω L = (521 . 504 Hz) (2 . 9 H) = 1512 . 36 Ω and X C = 1 ω C . From the equation tan φ = X L- X C R we obtain 1 ω C = ω L + R tan φ, C = 1 ω bracketleftbigg 1 ω L + R tan φ bracketrightbigg = 1 ω bracketleftbigg 1 X L + R tan φ bracketrightbigg = 1 521 . 504 Hz × 1 1512 . 36 Ω + (1200 Ω) tan 53 ◦ × 10 6 μ F 1 F = . 617598 μ F . 002 10.0 points Consider a series RLC circuit. The applied voltage has a maximum value of 150 V and oscillates at a frequency of 88 Hz. The circuit contains an inductor whose inductance can be varied, a 1000 Ω resistor, and a 1...
View Full Document

This note was uploaded on 01/21/2010 for the course PHY 303L taught by Professor Turner during the Spring '08 term at University of Texas.

Page1 / 5

hw 30 - nguyen (jmn727) – homework 30 – Turner –...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online