# ex1f08 - ECE473 EXAM #1 FALL 2008 Instructions : 1....

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Unformatted text preview: ECE473 EXAM #1 FALL 2008 Instructions : 1. Closed-book, closed-notes, open-mind exam. 2. Work each problem on the exam booklet in the space provided. 3. Write neatly and clearly for partial credit. Cross out any material you do not want graded. Name : Problem 1 : /20 Problem 2 : /20 Problem 3 : /20 Problem 4 : /40 Total : /100 Infinitely-Long Wire Carrying a Current i (A) or Charge q (C/m) : B = o H = o i 2 x , o = 4 10 7 H/m E = q 2 o x , o = 8 . 854 10 12 F/m Transmission Line Parameters : R = l A R 2 R 1 = T 2 + T T 1 + T L = 2 10 7 ln GMD GMR H/m C = 2 o lnGMD / GMR F/m r = re 1 / 4 = . 7788 r 1 mi = 1609 m 1 ft = 12 in 1 in = 2 . 54 cm 1 hp = 746 W 1 Problem 1 (20 Points) Conductor Outside Geometric Resistance (/mi) Resistance (/mi) Size Diameter Mean 25 o C 50 o C Radius (cmil) (in) (ft) dc 25 Hz 50 Hz 60 Hz dc 25 Hz 50 Hz 60 Hz 300 000 0.629 0.01987 0.1950 0.1953 0.1961 0.1966 0.213 0.214 0.214 0.215 A 300,000-cmil copper conductor with 19 strands is being considered for a single-phase two-wire...
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## This document was uploaded on 11/01/2011 for the course ECE 473 at Boise State.

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ex1f08 - ECE473 EXAM #1 FALL 2008 Instructions : 1....

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