points of difference between resistance and resistivity and resistor and rheostat.
Answers
Answer:
Resistivity is only proportional to the nature and temperature of the particular material. The SI unit of resistivity is Ohms-meter.
Answer:
Resistance is defined as the property of the conductor which opposes the flow of electric current. It is also defined as the ratio of the voltage applied to the electric current flowing through it. The resistance of a conductor depends on the length, area of cross-section, and the nature of the material that is used in the manufacturing of the conductor. For a conductor, the resistance is directly proportional to the length of the conductor and inversely proportional to the area of cross-section.
Resistivity is defined as the resistance offered by the material per unit length for unit cross-section. The SI unit of resistivity is Ohm.meter. Resistivity increases linearly with temperature. The resistivity of conductors is low when compared to the resistivity of the insulators. Therefore, it can be represented as:
Resistivity of conductors < Resistivity of alloys < Resistivity of insulators.
Explanation:
Differentiating Property Resistance Resistivity
1 Definition Resistance is the physical property of a substance because of which it opposes the flow of current i.e. electrons. Resistivity is the physical property of a particular substance which is having particular dimensions.
2 Proportionality Resistance is directly proportional to the length and temperature while it is inversely proportional to the cross-sectional area of the material. Resistivity is only proportional to the nature and temperature of the particular material.
3 Symbol R ρ
4 Formula R = V/I or,
R = ρ(L/A)V = Voltage, I = Current, ρ = Resistivity ρ = (R×A)/L
R = Resistance, L= Length, A = Cross-sectional area
5 SI Units The SI unit of resistance is Ohms The SI unit of resistivity is Ohms-meter.
6 Applications The property of resistance is used in several places like heaters, fuses, sensors, etc. Electrical resistivity measurement is used as a quality control test for calcareous soil.