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current

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  • marceugeneramboyong
    Electric current is the flow of electric charge. The SI unit of electric current intensity is the ampere. Electric current is measured using an ammeter. The
    Message 1 of 18 , Nov 1, 2008
      Electric current is the flow of electric charge. The SI unit of
      electric current intensity is the ampere. Electric current is measured
      using an ammeter.

      The electric charge may be either electrons or ions. The nature of the
      electric current is basically the same for either type.
    • jessica_timpug
      Electric current is the flow of electric charge. The electric charge may be either electrons or ions.
      Message 2 of 18 , Jan 10, 2009
        Electric current is the flow of electric charge. The electric charge
        may be either electrons or ions.
      • Chsselyn
        Suppose a potential difference is established between two points, and some charges are released. These charges will be acted on by the electrical force and
        Message 3 of 18 , Oct 27 6:01 AM
          Suppose a potential difference is established between two points, and some charges are released. These charges will be acted on by the electrical force and start to move. If we measure the amount of charge that flows by a given point in a certain time interval, we can define the current (i.e. the charge flowing through that point per unit time) via
        • Janica Viancci
          Whenever charges of a like sign move, we say there is a current. This is in many ways like a water current. We define current as the rate that charge passes
          Message 4 of 18 , Jul 9, 2010
            Whenever charges of a like sign move, we say there is a current. This is in many ways like a water current. We define current as the rate that charge passes through a given area, (a wire for instance). The units of current are known as amperes (A) and they are equivalent to 1 coulomb per second. By convention, we give current the same direction (+ or -) as the flow of positive charge. Ordinarily, the direction of the flow of current is opposite the flow of electrons. Although we now realize that it is the electron flow that we should have used, it doesn't really matter, mathematically, it works out either way. Besides, we've been using the positive-based system for over two hundred years, and old habits die hard.

            You probably know that the speed of light is incredibly fast. You may be wondering: "When I turn on my lights, how do all those little electrons make it to the end of the wire that quickly? Don't they bump into things?" The answer to this question is yes, they do bump into things. Quite often, actually. They zigzag wildly, smashing into the atoms in the conductor. This in turn raises the temperature of the conductor, as some of the energy of the electrons is converted into thermal energy. But back to your light switch, imagine the wires in your house are tubes, filled with electrons. (They are, by the way). When you push more electrons in one end, some fall out the other end. Although any given eletron may not move that far when you put it in the end closest to you, the electrons on the end will be pushed out long before you could blink.

            We use a quantity known as drift speed when we want to know the actual average velocity of the electrons as they catapult themselves down that tube. Drift speed is given by the equation:
            [Vd=I/(n*q*A)]
            where Vd is drift speed in meters per second, I is current in amperes, n is the number of mobile charge carriers per unit volume, q is the charge on each carrier, and A is the area of a cross-section of the tube.

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          • valenzuelajudevince
            Whenever charges of a like sign move, we say there is a current. This is in many ways like a water current. We define current as the rate that charge passes
            Message 5 of 18 , Jul 9, 2011
              Whenever charges of a like sign move, we say there is a current. This is in many
              ways like a water current. We define current as the rate that charge passes
              through a given area, (a wire for instance). The units of current are known as
              amperes (A) and they are equivalent to 1 coulomb per second. By convention, we
              give current the same direction (+ or -) as the flow of positive charge.
              Ordinarily, the direction of the flow of current is opposite the flow of
              electrons. Although we now realize that it is the electron flow that we should
              have used, it doesn't really matter, mathematically, it works out either way.
              Besides, we've been using the positive-based system for over two hundred years,
              and old habits die hard.

              You probably know that the speed of light is incredibly fast. You may be
              wondering: "When I turn on my lights, how do all those little electrons make it
              to the end of the wire that quickly? Don't they bump into things?" The answer to
              this question is yes, they do bump into things. Quite often, actually. They
              zigzag wildly, smashing into the atoms in the conductor. This in turn raises the
              temperature of the conductor, as some of the energy of the electrons is
              converted into thermal energy. But back to your light switch, imagine the wires
              in your house are tubes, filled with electrons. (They are, by the way). When you
              push more electrons in one end, some fall out the other end. Although any given
              eletron may not move that far when you put it in the end closest to you, the
              electrons on the end will be pushed out long before you could blink.

              We use a quantity known as drift speed when we want to know the actual average
              velocity of the electrons as they catapult themselves down that tube. Drift
              speed is given by the equation:
              [Vd=I/(n*q*A)]
              where Vd is drift speed in meters per second, I is current in amperes, n is the
              number of mobile charge carriers per unit volume, q is the charge on each
              carrier, and A is the area of a cross-section of the tube.
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