Question

how does the resistance of a wire depends on its length give a reason for your answer?

Answer 1

The resistance of the wire depends on it's length,in the following way -

• According to the Ohm's law, the resistance of a conductor is directly proportional to the length of that conductor.
• The resistance in a conductor occurs because the charge carrying electrons faces collision with the atoms of the conductor itself, which reduces the motion of the charge carrying electrons as well as the amount of electricity flow.
• Now,for a greater length of the conductor the electrons have to pass through greater number of atoms and number of collisions will also increase. With the increasing collision the resistance will increase too.
• That's why we observe a directly proportional relationship between the length and resistance of the conductor.