(a) Give two examples of substances which are good conductors of electricity. Why do you think they are good conductors of electricity?
(b) Calculate the resistance of a copper wire 1.0 km long and 0.50 mm diameter if the resistivity of copper is 1.7×10−8Ωm.
(a) Give two examples of substances which are good conductors of electricity. Why do you think they are good conductors of electricity?
(b) Calculate the resistance of a copper wire 1.0 km long and 0.50 mm diameter if the resistivity of copper is 1.7×10−8Ωm.
a)
Silver and Copper
Silver is the best conductor of electricity because it contains a higher number of movable atoms (free electrons). For a material to be a good conductor, the electricity passed through it must be able to move the electrons; the more free electrons in a metal, the greater its conductivity. However, silver is more expensive than other materials and is not normally used unless it is required for specialized equipment like satellites or circuit boards. Copper is less conductive than silver but is cheaper and commonly used as an effective conductor in household appliances.
(b)
R=pLA
R=1.7× 10−8× 1.0× 103π×(0.25×10−3)2
R = 85 Ω
a)
Silver and Copper
Silver is the best conductor of electricity because it contains a higher number of movable atoms (free electrons). For a material to be a good conductor, the electricity passed through it must be able to move the electrons; the more free electrons in a metal, the greater its conductivity. However, silver is more expensive than other materials and is not normally used unless it is required for specialized equipment like satellites or circuit boards. Copper is less conductive than silver but is cheaper and commonly used as an effective conductor in household appliances.
(b)
R=pLA
R=1.7× 10−8× 1.0× 103π×(0.25×10−3)2
R = 85 Ω
