hw3 - Physics 21 Fall, 2008 Solution to HW-3 Electric Field...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Physics 21 Fall, 2008 Solution to HW-3 Visualizing Electric Field Lines Answer several multi- ple choice questions about feld lines. (a) For a sheet o± negative charge, the feld is (choice D) (b) This diagram is wrong because (choice A) feld lines can- not cross each other, and because (choice B) symmetry re- quires the feld lines to be parallel. (c) The feld o± an electric dipole is (choice B) (d) This diagram is wrong because (choice C) the feld lines should be smooth curves, and the (choice D) feld lines should always end on negative charges or at infnity. (e) From the diagram below we can see Q A > 0and Q B < 0 ±rom the direction o± the feld lines. The lines are more dense near Q A ,so | Q A | > | Q B | . Only the second choice ( Q A =+7 q , Q B = - 3 q ) satisfes both these relations. Electric Field inside a conductor Answer several mul- tiple choice questions about the charges in a conducting rod suspended in an electric feld E directed towards the right. (a) The (positively charged) nuclei experience a ±orce to the right, and the (negative) electrons a ±orce to the le±t. (b) The electrons move to the le±t, and the nuclei are al- most stationary (the nuclei move slightly to the right). The nuclei are much more massive than the electrons, so their acceleration a = F/m = eE/m is much less.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/09/2009 for the course PHYS 021 taught by Professor Hickman during the Fall '08 term at Lehigh University .

Page1 / 2

hw3 - Physics 21 Fall, 2008 Solution to HW-3 Electric Field...

This preview shows document pages 1 - 2. Sign up to view the full document.

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