The resistance of a conductor depends on :

1. the temperature of the conductor
2. the thickness of the conductor
3. the length of the conductor
4. all of the above

all of the above

Reason — The three factors on which the resistance of wire depends are —

1. Dependence on length of the wire — the resistance of a wire is directly proportional to the length of the wire.
   R ∝ l
2. Dependence on the thickness of the wire — the resistance of a wire is inversely proportional to it's area of cross section (a) normal to the direction of flow of current.
   R ∝ $\bold{\dfrac{1}{a}}$
3. Dependence on the temperature of the wire — the resistance of conductor increases with an increase in it's temperature.