Check Your Understanding Copper wires use routinely used for extension cords and house wiring for several reasons. Copper has the highest electrical conductivity rating, and therefore the lowest resistivity rating, of all nonprecious metals. Also important is the tensile strength, where the tensile strength is a measure of the force required to pull an object to the point where it breaks. The tensile strength of a material is the maximumamount of tensile stress it can take before breaking. Copper has a high tensile strength, 2 × 10 8 N m 2 A thirdimportant characteristic is ductility. Ductility is a measure of a material’s ability to be drawn into wires and a measure of the flexibility of the material, and copper has a high ductility. Summarizing, for a conductor to be a suitable candidate for making wire, there are at least three important characteristics: low resistivity, high tensile strength, and high ductility. What other materials are used for wiring and what are the advantages and disadvantages?
Check Your Understanding Copper wires use routinely used for extension cords and house wiring for several reasons. Copper has the highest electrical conductivity rating, and therefore the lowest resistivity rating, of all nonprecious metals. Also important is the tensile strength, where the tensile strength is a measure of the force required to pull an object to the point where it breaks. The tensile strength of a material is the maximumamount of tensile stress it can take before breaking. Copper has a high tensile strength, 2 × 10 8 N m 2 A thirdimportant characteristic is ductility. Ductility is a measure of a material’s ability to be drawn into wires and a measure of the flexibility of the material, and copper has a high ductility. Summarizing, for a conductor to be a suitable candidate for making wire, there are at least three important characteristics: low resistivity, high tensile strength, and high ductility. What other materials are used for wiring and what are the advantages and disadvantages?
Check Your Understanding Copper wires use routinely used for extension cords and house wiring for several reasons. Copper has the highest electrical conductivity rating, and therefore the lowest resistivity rating, of all nonprecious metals. Also important is the tensile strength, where the tensile strength is a measure of the force required to pull an object to the point where it breaks. The tensile strength of a material is the maximumamount of tensile stress it can take before breaking. Copper has a high tensile strength,
2
×
10
8
N
m
2
A thirdimportant characteristic is ductility. Ductility is a measure of a material’s ability to be drawn into wires and a measure of the flexibility of the material, and copper has a high ductility. Summarizing, for a conductor to be a suitable candidate for making wire, there are at least three important characteristics: low resistivity, high tensile strength, and high ductility. What other materials are used for wiring and what are the advantages and disadvantages?
Two wires have the same resistance and radius. If the wires are made of iron and gold with resistivities respectively of 10.0 ✕ 10−8 Ω · m and 2.44 ✕ 10−8 Ω · m, determine the ratio of their lengths.
LFe
LAu
= ?
The rod given in the figure is made up of two different materials. Both have square crosssections of 3 mm side. The resistivity of the first material is 4 x 10-3 Ω.m and it is 25 cmlong while second material has resistivity of 5 x 10-3 Ω.m and is of 70 cm long. What is theresistivity of rod between its ends?
The LED requires a minimum current of 20.0 mA to light. Assuming that your battery is operating at 9.00 V, what would the resistance be if the LED just begins to light up when brought into contact with the end of your carbon resistor? [Answer in kΩ]