|
|
|
|
|
| Author |
Message |
![[Post New]](/templates/default/images/icon_minipost_new.gif) 24 Feb 2007 12:24:12 IST
|
|
|
current is a scalar quantity though we can associate some direction with it intuitively.
It is somewhat like the difference between speed and velocity. Current is defined to be the quantity of charge that flows past a point in a wire per unit time. In many cases the direction of the charge flow changes from one point to another, but the amount of charge passing a given point in a wire is the same at all points. There is a related vector quantity that you will encounter in the more advanced treatments of electricity and magnetism called the current density, usually designated by J. It appears in the differential form of Ampere's law. It is the charge per unit area per unit time in the direction of the charge flow. In a wire, the magnitude of the current density is I/A where A is the cross sectional area of the wire.
|
The Scientist does not study nature because it is useful; he studies it because he delights in it, & he delights in it because it is beautiful. If nature were not beautiful, it would not be worth knowing, life would not be worth living. Ofcourse I do not here speak of that beauty that strikes the senses, the beauty of qualities & appearances; not that I undervalue such beauty, far from it, but it has nothing to do with science; I mean that profounder beauty which comes from the harmoniuos order of the parts, & which a pure intelligence can grasp. |
this reply: 5 points
(with 1 
in 1 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
|
|
|
|
|
|
|
Moderation Team
![[Up]](/templates/default/images/icon_up.gif "[Up]"){kind=icon}
