Saved Bookmarks
| 1. |
A long straight non-conducting string carriers a charge density of `40 muC//m`. It is pulled along its length at a speed of `300 m//sec`. What is the magnetic field at a normal distance of `5 mm` from the moving string?A. `B=4.8 xx 10^(-7)T`B. `B=3.2 xx 10^(-7)T`C. `B=2.5 xx 10^(-7)T`D. `B=5 xx 10^(-7)T` |
|
Answer» Correct Answer - A The moving string behaves like a current, `i=(40 xx10^(-6)C//m)(300 m//sec)` `=1.2 xx 10^(-2)` ampare Then `B=(mu_(0)i)/(2 pi r)=(2 xx 10^(-7)xxx1.2 xx 10^(-2))/(0.005)` `=4.8xx10^(-7)` tesla |
|