ch20-h1-solutions

ch20-h1-solutions - liu (ql744) ch20-h1 chiu (56565) This...

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

This print-out should have 22 questions. Multiple-choice questions may continue on the next column or page – fnd all choices beFore answering. 001 10.0 points Which oF the Following statements about the discharging oF a capacitor through a light bulb are correct? List all that apply separated by commas. IF none are true, type “none”. A. The Fringe feld oF the capacitor decreases as the charge on the capacitor plates de- creases. B. Electrons ±ow across the gap between the plates oF the capacitor, thus reducing the charge on the capacitor. C. The electric feld at a location inside the wire is due to charge on the surFace oF the wires and charge on the plates oF the capacitor. D. Electrons in the wires ±ow away From the negative plate toward the positive plate, reducing the charge on the plates. Correct answer: A,C,D. Explanation: a) Electric feld in a capacitor is propor- tional to the surFace charge oF the capacitor plate. The more charge in the plate, the more intensity oF Fringe feld. b) This answer is wrong because electron does not ±ow through the space and reach other plate. c) This answer is correct because electric feld obeys superposition principle. Because both wire and surFace charge creates an elec- tric feld, any points inside the wire will be a combination oF electric felds. d) This answer is correct because charges can ±ow through the wire. 002 (part 1 of 6) 5.0 points Ap a r t i c u l a rc a p a c i t o ri si n i t i a l l yc h a r g e d . Then a high-resistance Nichrome wire is con- nected between the plates oF the capacitor, as shown in ²igure 1. The needle oF a compass placed under the wire de±ects 20 o to the east as soon as the connection is made. AFter 60 seconds the compass needle no longer de±ects. (I) i i i (II) i i i (III) Which oF the diagrams in ²igure 1 best in- dicates the electron current at three locations in this circuit: 0.01 seconds aFter the circuit is connected? 1. ²igure II 2. ²igure III correct 3. ²igure I Explanation: The capacitor is discharging, so the electron current decreases exponentially. Thus, the correct diagrams are: 1. (²igure III) 2. (²igure II) 3. (²igure I) 003 (part 2 of 6) 5.0 points 15 seconds aFter the ciruit is connected?

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.

This note was uploaded on 10/25/2011 for the course PHY 303L taught by Professor Turner during the Spring '08 term at University of Texas at Austin.

Page1 / 5

ch20-h1-solutions - liu (ql744) ch20-h1 chiu (56565) This...

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

View Full Document
Ask a homework question - tutors are online