To determine resistivity of two / three wires by plotting a graph for potential difference versus current.

It's done so because to find resistance according to Ohm's law, we are dividing the voltage by current. So when we find the slope, which is (Δy/Δx) of the straight-line graph (i.e., resistance), we need the voltage to be on the Y-axis (numerator of the fraction) and current on the X-axis (denominator). Hence, the other way round. - [Presenter] Let's explore how we can practically verify whether any material obeys Ohm's law. Now before we do that, let's quickly recall what Ohm's law is. Ohm's law says that if you take any material, like let's say, windings of a wire and if we apply a potential difference across the ends of that, so let's say the potential difference across the ends of this wire is V, and because of this, a current starts running over here, let's call that current as I. Then Ohm's law says that V must equal I times R. Where R represents the resistance that the material offers to the flow of charges through that material. And we have talked in detail about this in a previous video, so if you need a refresher it will a great idea to go back and watch that video and then come back over here. And so the question is, if I have some material with me, how do I check, practically, whether this relationship, Ohm's law, whether it really holds true or not. So to do this, we need to first understand a little bit more about this thing called resistance. You see, the resistance is a property of the material and its dimensions and something we'll talk more about in the fu...

Learning Objectives By the end of this section, you will be able to: • Differentiate between resistance and resistivity • Define the term conductivity • Describe the electrical component known as a resistor • State the relationship between resistance of a resistor and its length, cross-sectional area, and resistivity • State the relationship between resistivity and temperature What drives current? We can think of various devices—such as batteries, generators, wall outlets, and so on—that are necessary to maintain a current. All such devices create a potential difference and are referred to as voltage sources. When a voltage source is connected to a conductor, it applies a potential difference V that creates an electrical field. The electrical field, in turn, exerts force on free charges, causing current. The amount of current depends not only on the magnitude of the voltage, but also on the characteristics of the material that the current is flowing through. The material can resist the flow of the charges, and the measure of how much a material resists the flow of charges is known as the resistivity. This resistivity is crudely analogous to the friction between two materials that resists motion. Resistivity When a voltage is applied to a conductor, an electrical field E → E → is created, and charges in the conductor feel a force due to the electrical field. The current density J → J → that results depends on the electrical field and the properties of the materi...

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This problem has been solved! You'll get a detailed solution from a subject matter expert that helps you learn core concepts. See Answer See Answer See Answer done loading Question:Objective To prove Ohm’s Law by plotting a graph of potential difference versus current, and to determine the resistance and resistivity of a wire. Materials Required wire, voltmeter and ammeter, battery, rheostat, one way key, connecting wires Theory According to the Ohm's law, "The current flowing through a conductor is directly proportional to the Objective To prove Ohm’s Law by plotting a graph of potential difference versus current, and to determine the resistance and resistivity of a wire. Materials Required wire, voltmeter and ammeter, battery, rheostat, one way key, connecting wires Theory According to the Ohm's law, "The current flowing through a conductor is directly proportional to the potential difference across its ends provided the physical conditions (temperature, dimensions, pressure) of the conductor remains the same." If I be the current flowing through a conductor and V be the potential difference across its ends, then according to Ohm's Law: V = RI where, R is the constant of proportionality. R depends upon the material, temperature and dimensions of the conductor. The potential difference V is measured in volts and the current I in amperes, resistance R is in ohms. To establish the current-voltage relationship, it is to be shown that the ratio V / I remains constant for a gi...

Aim: To determine the resistivity of two/three wires by plotting a graph of potential difference versus current. Materials Required:  A resistance wire  A voltmeter and an ammeter of appropriate range  A battery (battery eliminator)  A rheostat  A metre scale  One way key  Connecting wires  A piece of sand paper  Screw gauge The Theory: What does Ohm's Law state? According to the Ohm's law, "The current flowing through a conductor is directly proportional to the potential difference across its ends provided the physical conditions (temperature, dimensions, pressure) of the conductor remains the same." If I be the current flowing through a conductor and V be the potential difference across its ends, then according to Ohm's Law, where, R is the constant of proportionality. It is known as resistance of the conductor. Or R depends upon the material, temperature and dimensions of the conductor. In S. units, the potential difference V is measured in volt and the current I in ampere, the resistance R is measured in ohm. How do we establish the current-voltage relationship? To establish the current-voltage relationship, it is to be shown that the ratio V / I remains constant for a given resistance, therefore a graph between the potential difference(V) and the current (I) must be a straight line. How then do we find the unknown values of resistance? It is the constant ratio that gives the unknown values of resistance, For a wire of uniform cross-section, the resistance dep...

In the previous article, we discussed Aim of the Experiment Aims of the ohm’s law experiment are as followings – • Verification of Ohm’s Law by showing that the Voltage to Current ratio is constant. • To determine the resistance of a wire by plotting a graph for potential difference (V) versus current (I) using Ohm’s Law. • To find the resistivity of a wire by plotting a graph for potential difference versus current. Theory of the Ohm’s law experiment From electric current and V = IR or, \color ………. (2) Where A is the cross-section area of the wire. A = πr 2 where r is the radius of the wire. L is the length of the wire. In this experiment, we will find the current and the potential difference across the sample wire by using Ammeter and Voltmeter respectively. Then the resistance of the wire can be found by using equation (1). Again, We have to take at least five sets of data for different voltages and currents. Then a graph is needed to plot the current along the positive Y-axis and the potential difference along the positive X-axis. • Ohm’s Law can be verified by finding the Voltage to current ratio. If the ratio remains constant [equation- (1)] for all sets of data, then we can say that the voltage across the resistance is proportional to the current through it which is nothing but Ohm’s Law. • One can easily find the value of resistance of the wire from the slope of the graph. R = \frac • One can find the resistivity of the wire from equation (2) by using the value of ...