N electrons each carrying charge e- are flowing across a unit cross se...
**Electric Current and its Direction**
Electric current is defined as the rate at which charge flows through a given cross-sectional area. It is a scalar quantity that represents the movement of electric charge in a specific direction. In this case, N electrons are flowing across a unit cross section of a metallic wire in unit time from east to west.
**Expression for Electric Current**
The expression for electric current can be written as:
I = nAvq
where,
- I is the electric current,
- n is the number of charge carriers per unit volume,
- A is the cross-sectional area of the wire,
- v is the drift velocity of the charge carriers, and
- q is the charge carried by each charge carrier.
**Direction of Electric Current**
The direction of electric current is defined as the direction in which positive charges would flow if they were the charge carriers. In reality, the charge carriers in metallic wires are electrons, which are negatively charged. Therefore, the direction of electric current is opposite to the direction of electron flow.
In this case, the electrons are flowing from east to west. So, the direction of electric current would be from west to east. This convention is known as the conventional current direction, which assumes that positive charges are flowing.
**Reasoning**
When a metallic wire is connected to a power source, the potential difference creates an electric field within the wire. This electric field exerts a force on the free electrons, causing them to move. The motion of these electrons constitutes an electric current.
In this scenario, N electrons are flowing across a unit cross section of the wire in unit time. The number of charge carriers per unit volume (n) is constant for a given material. The cross-sectional area of the wire (A) is also constant. The drift velocity (v) of the electrons is determined by the electric field and the resistivity of the wire.
As each electron carries a charge of e- (negative charge), the expression for electric current can be simplified as:
I = nAvq = N(e-)Av
Since the electrons are flowing from east to west, the direction of electric current is opposite to the electron flow. Therefore, the electric current would flow from west to east.
N electrons each carrying charge e- are flowing across a unit cross se...
I=Q/T
Electric current will flow feom west to east because the conventional flow of current will be always in the direction opposite to the direction of flow of electrons.
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