Physics Review Question Unit: Electricity and magnetism Year: 1997 Question#: 23 Question: Three identical metal spheres are mounted on insulating stands. Initially, sphere A has a net charge of q and spheres B and C are uncharged. Sphere A is touched to sphere B and removed. Then sphere A is touched to sphere C and removed. What is the final charge on sphere A? (1 ) q (2 ) q/2 (3 ) q/3 (4 ) q/4 What is this question really asking? Explanation by: Nathaniel W [ Return to question menu ] Answer 1 q INCORRECT Because the charge is reduced by a half, and there is a 1/4 of the original charge left in sphere C. return to top Answer 2 q/2 INCORRECT Because the original charge is halved twice. return to top Answer 3 q/3 INCORRECT Because the orignal charge is halved each time, not 1/3. return to top Answer 4 q/4 CORRECT Because the original charge is halved each time it contacts a neutral sphere, the charge on sphere C is fourthed. return to top What's this question really asking? How much does the original charge get reduced each time it is touched to another un-charged object. return to top |
[Home] [Lessons] [Review] [Search] [Links]
This web site is designed and maintained by Science Joy Wagon and may
not be reproduced or redistributed without written permission from Science Joy Wagon. |