hw 37 - nguyen (jmn727) homework 37 Turner (59070) 1 This...

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

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: nguyen (jmn727) homework 37 Turner (59070) 1 This print-out should have 9 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points A 1 . 4 mF capacitor is connected to a standard outlet ( rms voltage 57 . 3 V, frequency 81 Hz ). Determine the magnitude of the current in the capacitor at t = 0 . 00551 s, assuming that at t = 0, the energy stored in the capacitor is zero. Correct answer: 54 . 4838 A. Explanation: Let : V rms = 57 . 3 V , C = 1 . 4 mF = 0 . 0014 F , f = 81 Hz , and t = 0 . 00551 s . The capacitive reactance is X C = 1 C = 1 2 f C . The maximum current is I max = V max X C = 2 V rms X C = 2 (2 f C ) V rms . Because the current leads the voltage across a capacitor by 90 , at time t , I = I max sin ( t + 90 ) = 2 2 f C V rms sin (2 f t + 90 ) = 2 2 (81 Hz) (0 . 0014 F) (57 . 3 V) sin [2 (81 Hz)(0 . 00551 s) + 90 ] = 54 . 4838 A , so | I | = 54 . 4838 A . keywords: 002 10.0 points The emf E can drive the circuit below at any given frequency. E C L R A B D At what frequency does the light bulb glow most brightly? 1. both very low frequencies or very high frequencies correct 2. the frequency = LC 3. the frequency = 1 LC 4. very high frequencies 5. very low frequencies Explanation: Since the brightness of the bulb is propor- tional to the power dissipated in it, P = I 2 rms R, . In order to obtain maximum brightness we should adjust the frequency so that the rms current I rms through the bulb is the largest....
View Full Document

Page1 / 4

hw 37 - nguyen (jmn727) homework 37 Turner (59070) 1 This...

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

View Full Document Right Arrow Icon
Ask a homework question - tutors are online