Question

Which of the following are TRUE.

1) Resistance generally goes up with temperature because the atoms in materials become more aligned as temperature goes up.

2) Resistance generally goes up with temperature because the atoms in materials become more erratic as temperature goes up.

3) Resistance generally goes up with area because increasing area means increasing number of atoms involved in collisions.

4) Resistance generally goes up with length because increasing length means increasing the number of atoms involved in collisions.

Answer 1

4)Resistance generally goes up with length because increasing length means increasing the number of atoms involved in collisions.

Reason-In a conductor having a large number of free electrons flowing through it the vibration of the atoms causes many collisions between the free electrons and the captive electrons.Each collision is the basic cause of resistance.Due to increase in length more atoms brush against each other,more collisions are caused and hence the resistance increases.