InterviewSolution
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InterviewSolution
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(a) Use Gauss'slaw to derive the expression for theelectric filed (vecE) due tostraight uniformaly charges infinite line of charges density lambda C//m. (b) Draw a graphto show the variationof E withperpendicular from thelineof charge. (c) Find the work donein brining a charge q from prependicular distance r_(1) to r_(2) (r_(2) gt r_(1)). |
Answer» Solution :(a)  `cancel(O) = ointvecE .dveca` `cancel(O) = int E.da_(1) cos 90^(@) + intvecE.dveca_(2) cos 0^(@) + int vecE.dveca_(3) cos 90^(@)` `cancel(O) = int Eda_(2)` `cancel(O) = E_(2) pirl_(1)` `cancel(O) = (sumq)/(sum_(0)) = (lambdal_(1))/(sum_(0))` EQUATE them : `(dl_(1))/(sum_(0)) = E_(2)pirl_(1)` `E= (lambda)/(2pirsum_(0))` (b)  (c) WORK done to MOVING from `r_(1)` to `r_(2) dv underset(r_(1))overset(r_(2))int (lambda)/(2pisum_(0)r)dr` `dv = (lambda)/(2pirsum_(0))underset(r_(1))overset(r_(2))int(1)/(r) dr` `cancel(O) = (lambda)/(2pisum_(0))-[log.(r_(2))/(r_(1))]` `w = 9V` `w = 9((lambda)/(2pisum_(0))log((r_(2))/(r_(1))))` |
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