Relation between current and drift velocity

Conduction Electrons and Current Conduction Electrons and Current - 40 This page is more technical than those that proceeded it, although the math used is limited to algebra. If you have never taken a physics course and/or are reading this module just for the concepts, you may This is where more quantitative material will go when I have a chance. Covering the free electron model and the Drude model would be nice. For now, skip this page Many introductory physics texts discuss the microscopic origins of electric current and what factors determine the amount of current that will flow through a given wire. The animation below briefly recounts the key points. The reader is encouraged to grab his or her favorite physics text to obtain more details. A. Representative conduction electrons in a wire. (A real wire contains too many electrons to show; we have included only enough electrons to give a sense of what occurs.) B. In the absence of an electric field, electrons move randomly through the wire. C. In a sense, applying a potential difference to the wire is like tipping the wire. The electrons experience a net force toward the higher potential, resulting in a net velocity directed toward that higher potential. Much random motion, however, remains. The net velocity is called the drift velocity v d of the electrons. D. All of the charge D Q in the shaded volume D Vol of the figure will pass through the highlighted cross section of the wire in a time D t. The average current thro...

Hint: Rate of flow of charge is considered current. Here electrons are passing through a cross section in a particular direction. We consider the flow of current in direction opposite to electron flow as electrons have negative charge. Amount of current is given and time of flow of electrons in filament is also given. From this we can find out the time rate of flow of charge Formula used: $i = \dfrac $ Where ‘V’ is volume which will be the product of area(A) and displacement(x). cross section area ‘A’ is constant but displacement ‘x’ is varying. Rate of change of displacement is called drift velocity(v). Note: If charge is given as a function of time then we should differentiate that charge function with respect to time to get current and if current is given as a function of time then we can integrate with respect to time to find charge. We can also find average value of current and r.m.s value of current with that current function

Consider a conductor XY of length L and area of cross section A (Fig ). An electric field E is applied between its ends. Let n be the number of free electrons per unit volume. The free electrons move towards the left with a constant drift velocity v d. The number of conduction electrons in the conductor = nAL The charge of an electron = e The total charge passing through the conductor q = (nAL) e The time in which the charges pass through the conductor, t = L/v d The current flowing through the conductor, The current flowing through a conductor is directly proportional to the drift velocity. From equation (1), Hence

Resistivity is the quality of a material that creates a barrier for the electric current and hampers the speed and velocity of the material. The resistivity of a material is contrarily proportional to the drift of electrons. When the electrons present in the circuit move randomly, the net velocity of a circuit becomes 0, and the field of electricity is not applied to the circuit. What is resistance? An electron moving via the electric wires & loads of an external circuit experienced the resistance. The resistance is the hurdle to the flow of the charge. An electron does not move in a direct route between the terminals. It follows the zigzag pattern where the electron experiences several collisions with stable atoms in the conducting material. In other words, an electron experiences numerous hindrances during its movement from one terminal to another and it is known as electrical resistance. The SI unit to measure the electrical resistance is ohms (Ω). To further understand the Drift of electrons and the origin of resistivity , you can assume a graph with the current (I) to the voltage (V) ratio. You will notice that the current will flow with the points A, B, and C, but this will slowly turn to a constant state after a matter of time. This is the time the resistance will start performing its work. What is drift force? The electrons move or drift inside a conductor due to drift force. First, you should know that the subatomic particles contain random mobility, including the...

The main reason behind the occurrence of this current is because of the application of external forces it can be either electric field or voltages. Density in Semiconductors As the external supply is provided there is the movement in the majority of the concentration of the carriers. Based on the type of semiconductors its majority of the carriers vary. This net motion in the concentration of the particles that are either holes or electrons can be referred to as the drift current of that particular semiconductor. Drift Current Calculation : In this way, this current is calculated. It is measured in terms of Amperes. The velocity achieved by the charge carriers due to the application of external voltage is referred to as Drift velocity. The drift velocity for the carrier concentration of electrons is Drift velocity of the holes concentration is Vp= µ pE Here Vp is the drift velocity referred to the concentration of holes µ p refers to the mobility of the concentration of holes and E representing the electric field acting upon it. General Relation between Current and Drift Velocity Suppose that there are n number of electrons per cubic centimeter as well as the drift velocity (V d). In a certain moment of time, the electron tends to move this is referred to as the distance V d∆t. Its volume is AV d∆t Then the motion of a number of free electrons in that particular region is AV d∆t Similarly, the charge crossed across the area is given by ∆q = nqAV d∆t Therefore I= ΔQ/ Δt = n...

Hint: Knowledge of charge transport phenomenon in conductors is vital to solve this problem. Making a circuit diagram of the charge transport phenomenon will assist in solving this problem easily. Drift velocity $ '. $ Complete step-by-step answer: Let’s make a diagram of current flowing through a conductor to get an idea for the charge transport phenomenon in a conductor. We will consider the length of the conductor to be ‘l’ and the cross sectional area of the conductor to be ‘A’. Further, the free electron density of the conductor is ‘n’ electrons per meter cube. The conductor contains multiple cations and multiple electrons as shown in the diagram above. When a potential difference ‘V’ is applied as shown in the diagram, an electric field ‘E’ will be produced across the conductor from the positive terminal towards the negative terminal. The free electrons of the conductor travel in the opposite direction of the applied electric field. Hence, the electrons travel from the negative end of the conductor (as marked in the diagram) towards the positive end of the conductor (as marked in the diagram). The velocity with which these electrons travel is known as drift velocity of the electrons or just drift velocity of the conductor. The actual definition of drift velocity $ ' $ Note: It’s important to know as to why; we call the movement of electrons in the conductor from the negative end towards the positive end in the presence of an externally applied electric field as drift...