Answer:
Length of conductor. 
Step-by-step explanation:
The devices that resist the flow of electric current are called resistors. When an electric current of 1 ampere flows in a circuit that have potential difference of 1 volt, then 1 ohm of resistance exists in the circuit. Mathematical relationship can be written as :
 , R is resistance
 , R is resistance

Also, the resistance of a conductor is directly proportional to the length and inversely proportional to the area of cross section of the wire.


 is the resistivity of the material
 is the resistivity of the material
Hence, the resistance of a conductor is directly proportional to the length