This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: cherubin (mcc2645) Homework 3 DC Circuits Catala (12054) 1 This printout should have 24 questions. Multiplechoice questions may continue on the next column or page find all choices before answering. 001 10.0 points Consider the circuit shown in the figure. I 40 V 28 7 35 Find its equivalent resistance. Correct answer: 33 . 8333 . Explanation: I E R a R b R c Let : R a = 28 , R b = 7 , and R c = 35 . R c and R b are in parallel, so 1 R bc = 1 R b + 1 R c R bc = parenleftbigg 1 R b + 1 R c parenrightbigg 1 R bc = parenleftbigg 1 7 + 1 35 parenrightbigg 1 = 5 . 83333 R bc and R a are in series, so R eq = 28 + 5 . 83333 = 33 . 8333 . 002 (part 1 of 3) 10.0 points A total charge of 18 mC passes through a crosssectional area of a nichrome wire in 2 . 7 s. a) What is the current in the wire? Correct answer: 0 . 00666667 A. Explanation: Let : Q 1 = 18 mC and t 1 = 2 . 7 s . I = Q t = . 018 C 2 . 7 s = . 00666667 A . 003 (part 2 of 3) 10.0 points b) How many electrons pass through the crosssectional area in 17.0 s? Correct answer: 7 . 08333 10 17 . Explanation: Let : q e = 1 . 6 10 19 C and t 2 = 17 . 0 s . Q = N q e N = Q q e = I t 2 q e = (0 . 00666667 A)(17 s) 1 . 6 10 19 C = 7 . 08333 10 17 . 004 (part 3 of 3) 10.0 points c) If the number of charges that pass through the crosssectional area during the given time interval doubles, what is the resulting cur rent? Correct answer: 0 . 0133333 A. Explanation: Let : Q 2 = 2 Q 1 . cherubin (mcc2645) Homework 3 DC Circuits Catala (12054) 2 I = 2 Q 1 t 1 = 2 (0 . 018 C) 2 . 7 s = . 0133333 A . 005 (part 1 of 2) 10.0 points The power supplied to the circuit shown in the figure is 7.00 W. E 2 . 0 14 . 0 6 . 0 4 . 0 2 . 0 a) Find the equivalent resistance of the cir cuit. Correct answer: 3 . 60784 . Explanation: E R 1 R 2 R 3 R 4 R 5 Let : R 1 = 2 . 0 , R 2 = 14 . 0 , R 3 = 6 . 0 , R 4 = 4 . 0 , and R 5 = 2 . 0 ....
View
Full
Document
This note was uploaded on 06/10/2010 for the course PHY 100 taught by Professor Pro.kiroshima during the Spring '10 term at Adelphi.
 Spring '10
 PRO.KIROSHIMA
 Charge, Work

Click to edit the document details