i am a first year electrician in school and was taught the resistivity formula over the past couple days but i am having a hard time wrapping my head around it and was wondering if some one could help.
R in (Ω)=pL/A
so p for copper is 16.6 ohm-meters at 0.C and that number comes from the resistance (or Ω) of a cube 1mx1mx1m. so that is the Ω per m^3
so p= Ω/m^3. so if i took the area (m^2 and multiplied it by the length in m it would give me volume or m^3. so length times area times ohm gives me resitive value? well no but Ω/m^3* tm^3 = tΩ (the tm^3 coming from Am^2*Lm)
Ω=(Ω/m^3)*Lm/Am^2 = l*A*Ω? is confusing to me
Ω=(Ω/m^3)*Lm/Am^2 simplified is A^4 = L which obviously is not true
I=V/R where voltage and current are directly proportional R=V/I so for each material shouldn't there be ratio or coefficient that you could multiply times area giving you Ω per m^3 as your resistivity value, which you could assign a value create an si unit? (temperature coefficients to be factored later)
I don't know if this makes sense but if someone could see where im going wrong or explain the resistivity formula at greater depth or how it is derived would be appreciated thanks
R in (Ω)=pL/A
so p for copper is 16.6 ohm-meters at 0.C and that number comes from the resistance (or Ω) of a cube 1mx1mx1m. so that is the Ω per m^3
so p= Ω/m^3. so if i took the area (m^2 and multiplied it by the length in m it would give me volume or m^3. so length times area times ohm gives me resitive value? well no but Ω/m^3* tm^3 = tΩ (the tm^3 coming from Am^2*Lm)
Ω=(Ω/m^3)*Lm/Am^2 = l*A*Ω? is confusing to me
Ω=(Ω/m^3)*Lm/Am^2 simplified is A^4 = L which obviously is not true
I=V/R where voltage and current are directly proportional R=V/I so for each material shouldn't there be ratio or coefficient that you could multiply times area giving you Ω per m^3 as your resistivity value, which you could assign a value create an si unit? (temperature coefficients to be factored later)
I don't know if this makes sense but if someone could see where im going wrong or explain the resistivity formula at greater depth or how it is derived would be appreciated thanks