How do you find the resistance of a metallic conductor?

The resistance of a conductor is directly proportional to its length (L) as R ∝ L. Thus doubling its length will double its resistance, while halving its length would halve its resistance. Also the resistance of a conductor is inversely proportional to its cross-sectional area (A) as R ∝ 1/A.

What is the independent variable in the resistance practical?

In this experiment the: Independent Variable is the length of wire. Dependent Variable is the resistance of the wire. Control Variables are the material, the cross section area and the temperature of the wire.

How is the resistance of a metallic conductor affected by variation in temperature?

The resistance of a conductor increases with an increase in temperature because the thermal velocity of the free electrons increases as the temperature increases. This results in an increase in the number of collisions between the free electrons.

How do you find the resistance?

If you know the total current and the voltage across the whole circuit, you can find the total resistance using Ohm’s Law: R = V / I. For example, a parallel circuit has a voltage of 9 volts and total current of 3 amps. The total resistance RT = 9 volts / 3 amps = 3 Ω.

What is Ohm’s law experiment?

In this experiment, the current flowing through a resis- tor will be measured as the voltage across the resistor is varied. From the graph of this data, the resistance is determined for Ohmic resistors (Ri, i = 1, 2, 3). Non- Ohmic resistors (R4, light bulb) do not obey Ohm’s Law.

What variables affect the resistance of a material?

Factors That Affect Resistance How much resistance a material has depends on several factors: the type of material, its width, its length, and its temperature. All materials have some resistance, but certain materials resist the flow of electric current more or less than other materials do.

What is resistance of a metallic conductor?

Resistance of a metallic conductors increases with increase (or rise) in temperature. because the temperature coefficient of conductors is positive in nature hence resistance is directly proportional to temperature.

How does the resistance of a conductor vary?

The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area. Resistance also depends on the material of the conductor. The resistance of a conductor, or circuit element, generally increases with increasing temperature.

How do you find resistance with resistivity and length?

The resistance of a cylindrical segment of a conductor is equal to the resistivity of the material times the length divided by the area: R≡VI=ρLA. The unit of resistance is the ohm, Ω.

How do you find resistance from area?

Conductor resistance increases with increased length and decreases with increased cross-sectional area, all other factors being equal. Specific Resistance (”ρ”) is a property of any conductive material, a figure used to determine the end-to-end resistance of a conductor given length and area in this formula: R = ρl/A.

How does the length of the wire affect the resistance?

As the length of wire increases, the resistance will increase. The greater the length of wire the greater the number of collisions between the free electrons and metal ions. This will result in greater resistance. Do not handle the wire.

What are the independent and dependent variables of a wire?

Independent Variable is the length of wire. Dependent Variable is the resistance of the wire. Control Variables are the material, the cross section area and the temperature of the wire. These are kept the same by not changing the wire during the experiment, by keeping the current small and opening the switching between readings.

What happens when a current flows through a conductor?

Whenever a current flows through a conductor there is a heating effect. Electrical energy is converted to heat energy. To ensure the temperature of the wire does not increase, switch off between readings and keep the current as low as possible.

What are the control variables of a control wire?

Control Variables are the material, the cross section area and the temperature of the wire. These are kept the same by not changing the wire during the experiment, by keeping the current small and opening the switching between readings.