Question

Explain all the factors affecting resistance of a conducting wire

Answer 1

All conductors show some opposition to the flow of an electrical current. This opposition to current flow is called resistance. There are several factors that affect the resistance of a conductor;
material e.g. copper has lower resistance than steel
*length - longer wires have greater resistance
*thickness - smaller diameter wires have greater resistance
*temperature - heating a wire increases its resistance

Answer 2

Factors affecting the resistance:
1. Length of the conductor:
The resistance of a wire is directly proportional to length of the conductor i.e
R α l
The resistance increases with an increase in length of the conductor. On an increases in length greater number of collisions of electrons increases the resistance.

2. Temperature:
Temperature also affects the resistance. More is the temperature, faster the movement of electrons, more number of collisions of electrons increases the resistance.
Resistance increases with the increase in temperature. 

3. Thickness of the conductor:
More the thickness of the conductor, more is the cross sectional area, less number of collisions of electrons decreases the resistance.
The resistance of a conductor is inversely proportional to cross sectional area of the conductor
R α 1/a

4. Nature of the conductor:
The resistance of a wire depends on the nature of the conductor. For example: Copper is a good conductor of electricity while nichrome is a bad conductor conductor of electricity. 
The resistance depends on the properties of the conductor. 

Hope this helps you.