A carbon resistor is 9 mm long and has a constant cross section of0.3 mm2. The conductivity of carbon at room temperature is s = 3multiplied by 104 per ohm·m. In a circuit its potential at one endof the resistor is 10 volts relative to ground, and at the otherend the potential is 16 volts. A thin copper wire in the samecircuit is 9 mm long and has a constant cross section of 0.3 mm2.The conductivity of copper at room temperature is s = 6 multipliedby 107 ohm-1m-1. The copper wire is in series with the carbonresistor in the same circuit mentioned above, with one endconnected to the 16 volt end of the carbon resistor. Calculate theresistance R of the copper wire and the potential Vat end at theother end of the wire.
R =
Vat end = V
You can see that for most purposes a thick copper wire in a circuitwould have practically a uniform potential. This is because thesmall drift speed in a thick, high-conductivity copper wirerequires only a very small electric field, and the integral of thisvery small field creates a very small potential difference along th
A carbon resistor is 9 mm long and has a constant cross section of0.3 mm2. The conductivity of carbon at room temperature is s = 3multiplied by 104 per ohm·m. In a circuit its potential at one endof the resistor is 10 volts relative to ground, and at the otherend the potential is 16 volts. A thin copper wire in the samecircuit is 9 mm long and has a constant cross section of 0.3 mm2.The conductivity of copper at room temperature is s = 6 multipliedby 107 ohm-1m-1. The copper wire is in series with the carbonresistor in the same circuit mentioned above, with one endconnected to the 16 volt end of the carbon resistor. Calculate theresistance R of the copper wire and the potential Vat end at theother end of the wire.
R =
Vat end = V
You can see that for most purposes a thick copper wire in a circuitwould have practically a uniform potential. This is because thesmall drift speed in a thick, high-conductivity copper wirerequires only a very small electric field, and the integral of thisvery small field creates a very small potential difference along th
