This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: homework 13 – LEE, BENJAMIN – Due: Oct 4 2007, 4:00 am 1 Question 1, chap 27, sect 4. part 1 of 4 10 points Consider the circuit in the figure. . 10 A E S 3 Ω 5 Ω 8 Ω 7 Ω Find the potential difference across the 3.0 Ω resistor. Correct answer: 0 . 3 V (tolerance ± 1 %). Explanation: I E S R 1 R 2 R 3 R 4 Let : I = 0 . 10 A , and R 1 = 3 . 0 Ω . For resistors in series, I = I 1 = I 2 = I 3 = I 4 , and Δ V = I R . Δ V 1 = IR 1 = (0 . 1 A) (3 Ω) = . 3 V . Question 2, chap 27, sect 4. part 2 of 4 10 points Find the potential difference across the 5.0 Ω resistor. Correct answer: 0 . 5 V (tolerance ± 1 %). Explanation: Let : R 2 = 5 . 0 Ω . Δ V 2 = I R 2 = (0 . 1 A) (5 Ω) = . 5 V . Question 3, chap 27, sect 4. part 3 of 4 10 points Find the potential difference across the 8.0 Ω resistor. Correct answer: 0 . 8 V (tolerance ± 1 %). Explanation: Let : R 3 = 8 . 0 Ω . Δ V 3 = I R 3 = (0 . 1 A) (8 Ω) = . 8 V . Question 4, chap 27, sect 4. part 4 of 4 10 points Find the potential difference across the 7.0 Ω resistor. Correct answer: 0 . 7 V (tolerance ± 1 %). Explanation: Let : R 4 = 7 . 0 Ω . Δ V 4 = I R 4 = (0 . 1 A) (7 Ω) = . 7 V . Question 5, chap 28, sect 4. part 1 of 1 10 points A 25 V battery has an internal resistance r . 1 A 25 V r 24 Ω 40 Ω internal resistance What is the value of r ? Correct answer: 10 Ω (tolerance ± 1 %). Explanation: I 1 I 2 I 3 E r R 2 R 3 internal resistance Let : E = 25 V , R 2 = 24 Ω , R 3 = 40 Ω , and I 1 = 1 A . homework 13 – LEE, BENJAMIN – Due: Oct 4 2007, 4:00 am 2 Since R 2 and R 3 are connected parallel, their equivalent resistance R 23 is 1 R 23 = 1 R 2 + 1 R 3 = R 3 + R 2 R 2 R 3 R 23 = R 2 R 3 R 2 + R 3 = (24 Ω) (40 Ω) 24 Ω + 40 Ω = 15 Ω . R 1 and R 23 are in series, so by Ohm’s law, we have E = I 1 r + I 1 R 23 r = E  I 1 R 23 I 1 = 25 V (1 A) (15 Ω) 1 A = 25 Ω 15 Ω = 10 Ω . Question 6, chap 28, sect 4....
View
Full
Document
This note was uploaded on 04/07/2008 for the course PHY 303K taught by Professor Turner during the Fall '07 term at A.T. Still University.
 Fall '07
 Turner
 Work

Click to edit the document details