resistance=rho*length/area
rho=resistance*area/length so you can figure it out.
im confused... how should i solve this when there is no resistivity value given?
The resistance of a rod with a length of 3.0 m and diameter of 1.0 cm is 56.0 ohms. If this rod is stretch to form a wire with a diameter of 0.01 cm, what is its resistance? Assume that in the process of stretching the rod, its volume did not change.
2 answers
the resistance of a "wire" ... either short and heavy or long and thin
... is directly proportional to the length
... and inversely proportional to the cross sectional area (diameter squared)
volume = length * cross sectional area
find the length ... 3.0 m * (1.0 cm)^2 = ? m * (0.01 cm)^2
r = 56.0 Ω * (? m / 3.0 m) / (0.01 cm / 1.0 cm)^2
... is directly proportional to the length
... and inversely proportional to the cross sectional area (diameter squared)
volume = length * cross sectional area
find the length ... 3.0 m * (1.0 cm)^2 = ? m * (0.01 cm)^2
r = 56.0 Ω * (? m / 3.0 m) / (0.01 cm / 1.0 cm)^2
0 answers