CURRENT

• It is any movement of charges from one region to another is called what?


  Current
• The ________ _______ is defined as the net charge flowing through an area per unit time.


  electric current
• What is the direction of the current if it flows of positive charges?

  Same
• What is the direction of the current if it flows of negative charges?

  Opposite
• What is the SI unit of electric current

  C/s or A
• It is the limit if the average current as the time interval approaches zero.


  Instanteneous current
• Charges flowing through a surface can be ________, ________, or ____.

  positive, negative, both
• All currents are simply what?

  The averages of the charge passing through an area over time
• In plasma, these charges may include both _________ and __________________ ions.

  positively-, negatively-charged
• The direction of the current is the same as the flow of positive charges.


  Conventional current
• The direction of current is opposite as the flow of negative charges.


  Electron flow
• The electric field is ____ in a conductor.

  zero
• Since the motion of these electrons is ______, there is __ ___ ____ __ ______ in any specific direction; hence there is __ ______.

  random, no net flow of charge, no current
• A charged particle also moves ________ and experiences frequent __________ with __________ ions within the conductor.

  randomly, collisions, stationary
• What is the very slow net motion or drift of the moving charges in the direction of the steady electric force?


  drift velocity
• Why does there are no absolute value signs in the equation?


  Because the sign of q affects the direction of the drift velocity
• If q is positive, vd moves in the ____ direction as E.

  same
• If q is negative, vd then is in the ________ direction of E.

  opposite
• In both cases, the direction of J is _______ to the direction of E.

  similar
• In cases where there are different kinds of moving charges, concentrations, and magnitudes of drift velocities involved, how can we determine the total current for each charged particle?

  Using superposition principle
• It has an SI unit of coulomb per second (C/s) or the ampere (A).


  Electric current
• It is the current per unit cross-sectional area. It has a unit of amperes per square meter (A/m2).


  Current density