2006-10-23 02:51:22 · 7 answers · asked by suresh t 1 in Education & Reference ➔ Higher Education (University +)
Since nothing visibly moves when the charge-sea flows, we cannot measure the speed of its flow by eye. Instead we do it by making some assumptions and doing a calculation. Let's say we have an electric current in normal lamp cord connected to bright light bulb. The electric current works out to be a flow of approximatly 3 inches per hour. Very slow!
Here's how I worked out that value. I know:
Bulb power: about 100 watts, about 100V at 1A
Value for electric current: I = 1 ampere
Wire diameter: D = 2/10 cm, radius R=.1cm
Mobile electrons per cc (for copper, if 1 per atom): Q = 8.5*10^+22
Charge per electron: e = 1.6*10^-19
The equation:
cm/sec = ________I_______ = .0023 cm/sec = 8.4 cm/hour
Q * e * R^2 * pi
This is for DC. Chris R. points out that for a particular value of frequency of AC, the "skin effect" can cause the flow of charges in the center of a wire to be reduced while the current on the surface becomes stronger. There are fewer charges flowing, and hence they must flow faster. ("Skin Effect" is stronger at high frequencies and with thick wires. The effect can USUALLY be ignored in thin wires at 60Hz power-line frequencies.)
reff:http://amasci.com/miscon/speed.html
2006-10-23 02:54:50 · answer #1 · answered by santhana k 3 · 0⤊ 0⤋
there is nothing like spped of current.. actually current is nothing but the flow of electrons in a particular directions caused due to some force (potential diffence, charge gradiance etc). Even the current is defined sometimes as "the flow of electorns" so if you really want to calculate the speed of current .. you need to calculate the speed of electrons that constitute the current.
What i think would serve your purpose is take 1 ampere of current as a value of current.. see (calculate) how many electrons would make up that amount (1 amp/charge on single electron ) , i assume time to be 1 second here ( I guess if i am not mistaken , current (I) = charge (Q) /Time (t).
now once you know the number of electrons, you can calculate the momemtum ( and in tern the speed, as you know the mass of a single electron), by using the Heisenberg's uncertainity principle. (i forgot the excat equation.. ops :) )
hope this would help you if not serve your purpose.
2006-10-23 14:17:28 · answer #2 · answered by saurabh 1 · 0⤊ 0⤋
The speed of current is 1000000 metre/second
2006-10-23 11:48:18 · answer #3 · answered by bala m 1 · 0⤊ 0⤋
7000 K/M/Min is speed of Current
2006-10-23 11:07:42 · answer #4 · answered by devraj s 1 · 0⤊ 0⤋
current is induced as a result of electron flow,, so its the electrons tht are moving, and they move approximately 3x10^8 m/s.
but in actual practice the electron's speed might b a bit less than tht.
2006-10-23 10:02:34 · answer #5 · answered by pHatman 3 · 0⤊ 0⤋
43 5. INTERNAL WAVES Internal waves occur in the interior stratified region of strong temperature/density gradients (PDF)
This leads to a series of slicks/smooth and. ruffled/rough sea surface. ... The mean amplitude of the solution is 25 m, the nonlinear phase speed is 1.7 ...
http://www.nio.org/monographs/LVG_Rao/LVG_chap5.pdf -
2006-10-26 12:00:37 · answer #6 · answered by Krishna 6 · 0⤊ 0⤋
The rate of flow of the electrons.
Pls check the site
http://www.newton.dep.anl.gov/newton/askasci/1993/physics/PHY112.HTM
2006-10-23 09:58:34 · answer #7 · answered by Rainbow 4 · 0⤊ 0⤋