ece312_au10_exam1sol

ece312_au10_exam1sol - Problem 1 13 parts, 40 points) A...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

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

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

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

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Problem 1 13 parts, 40 points) A current density .7 = 52 A/m2 flows through the cross section of an infinitely long hollow cylinder as shown. The hollow cylinder has inner radius 10 cm, outer radius 25 cm, and u = 1000 no, While the space inside and outside the cylinder has it = no. Be sure to include both magnitude and direction when providing vector answers. 3 flows in hollow cylinder cross section (infinitely long) (a) Find the magnetic field intensity on the axis of the cylinder (Le. at r = 0 ). (10 points) A A F $.38: #:“w m m it sin ens Magnesiecmi «K its ‘ ' a mrgcmtiiifir b £32; iwfisim ,, easements ‘3 ism jigs ' ' Q PM: ’ ‘ “2‘3ka X} Sigiwmifik him “\"Bmg‘mm Pam; iigivrf} mei§ at; 9g? fi“-~»% l x v G '- “1“” W“ i: ‘This meefi hwswsiesf gin a; : “t gains \ I. ” i a: “a. M \ figkgggfla¥flw 4%” Efive if? in: items. ifiiw' imhfiim C “in ice fiat 70ming ($52“? kw {%€§%'® with em Raga} {i-g’ @fifieg if? ‘Tkwj; fig i x rd “mg: g rs } h" gfifiwb, 1i i M Li . ' ' ’i w“ V "in u - ‘ i a‘“ L A« is Q} W? fig Mk fling. I . m i Max (b) Find the magnetic flux density at r = 15 cm. (15 points) _ W R U tn; sigh it“; t5 ifig hgt'lité fiat,“ f“ r? .. r W ESQ alfm W km . «2;. ’ 't m“ mm“ B Ni ‘ -‘ Xian. Urt‘lh égflfi wgfggéigmjgfifififfi mm taming-“E s .' a“; L r. -‘ M tr“ ms?» t we we E‘s“ mtg, w» lessen Esta wfi§%&m% gazfia g mar-um fink-3e; ' ’5 19‘s5 Ewfifi Mada “a ’QI figfigfiwf gaging fit a? ) I - as. ‘ 1 khflifl" SAKX‘ZJw Wm - “f m e A 1 - 1 t I a tafilfim‘fi‘ l & Wm w; ‘5” M j; @ {Eagmgg glam? ms new"? t «a? “3“” ‘ ’ A’" $9“ My“? H 6% * j; T L“, “Millikanmu, “www.mme ‘ (c) A small Wire of length 1 cm carrying current I A in the —2 direction is placed at the point (r r 30 cm, (1) = 0, z = l m). Find the force that results on this small wire. (15 points) “m” Jayme” W am A . may fm “fie-Em ' 3% “ti Jr w ‘ at M as t; “til” “‘33” E: W i a g; at x g gm y: g “26 e g; 5 wail-Egg “My”; ‘M. W “fix tit-N it“? A s it. m. -‘-’ ‘ n f“ “t4 ts t?” a WWW. a j Problem 2 (3 parts: 40 points: A stretchable circular loop of Wire lies in the x-y plane as shown. The loop is expanding in the radial direction at a velocity of 0.1? m/s on all portions of the loop. At time zero, the radius of the loop is 50 cm. A y | Loop is expanding in radial direction at velocity 0.1 m/s (a) If the loop exists in a magnetic flux density 3 = —32 T, find the magnitude of the EMF induced in the loop at time zero. (15 points) 33% ft?“ t t m g H *‘ Mhmfi gs: Wtfimfi (b) Do induced currents flow clockwise or counterclockwise in the figure at time zero? Explain your answer — no credit for unexplained guesses. (10 points) g E Q l E = s is. m: ,' 'é ., ‘ ,- fl '3; 5; ‘fi W% in In; Mémaflé vegan e’m EM? gfifigfmj Kggv gagsf’ 9 r 1’ flash , V we} igflkgfi‘ WW5); ii" - :9“ "W i "W k é i i V A;- ‘s . a ‘5‘ - ‘2‘ A “1% l %m¢ W glam % We 1 wigs {ng maid? his elite “it; i a I *4“ ' t E“ -- ‘ ‘ it . t ' ‘l‘ é} “em aw _ we gfiagegi if” M, mg”? gififimtaéfia g gfiggg ggégfir” ..A q was” 5 (c) This expanding loop is instead placed in the presence of f3 = 2(6r) sin(2r) + 5‘5 cos(2 r) T, where r is the cylindrical coordinate in meters and r is time in seconds. Find the absolute value of the (total) EMF induced in the circuit at time zero. (15 points) Problem 3 5 arts 4 oints each : Circle the best answer. (1) Which of the following is the phasor expression for E = itsin (oat — z) + j;cos(cor + z) ? (d) E = + one” (e) none of the above (2) Which of the following electric fields would not satisfy Maxwell’s equations in source-free free space? @«t‘i‘ccos [mt —9 V/m .x‘" (b) ficosflntifl V/m (c) icos[mt-§ V/m (d) J‘ccos (wt + g) V/m (e) none of the above (3) The displacement current term in Maxwell’s equations: (a) results in a modified F araday’s Law (b applies to magnetostatic situations @s necessary to ensure consistency with the law of charge conservation ) describes the voltage across an inductor (e) none of the above (4) The inductance of a cylindrical solenoid: (a) decreases as the permeability of the material inside the solenoid is increased (b) will double if the number of turns of wire in the solenoid is doubled (0) increases as the length of the solenoid is increased (keeping the number of turns constant) )(does not depend on the radius of the solenoid LEfirone of the above (5)—A boundary exists between free space (2 > 0) and a medium (2: < 0) having a = 480 and n = 2u0 . The fields in the free space region are E = )“c + 42' (V/m), [’3’ i j; + 22 (A/m) While in the lower region the fields are E 2 at + 2 (Wm) and 1—7! I 2}“) + :7 (A/m). What is the surface 1 anion the boundary? 3? j (0))? (d) 2 current density .75 ( (a) 0 ‘x (b) (e) none of the above W ...
View Full Document

This note was uploaded on 01/11/2012 for the course ECE 312 taught by Professor Johnson,j during the Fall '08 term at Ohio State.

Page1 / 5

ece312_au10_exam1sol - Problem 1 13 parts, 40 points) A...

This preview shows document pages 1 - 5. Sign up to view the full document.

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