Which changes would cause an increase in the resistance of a wire? Check all letters that apply.

a) increasing its temperature

b) decreasing its temperature

c) using a longer wire

d) using a shorter wire

e) using a thicker wire

using a thinner wire

The correct answers are:

A) increasing its temperature

C) using a longer wire

G) using a thinner wire

A) When we increase the temperature of the wire, the atoms of the wire move more and faster, so if a current passes through the wire, the electrons of the current collide more with the atoms of the wire: thus, the resistance increases.

C) When we use a longer wire, the current must flow through a longer path, thus the electrons of the current collide more with the atoms of the wire, and the resistance increases.

G) When we use a thinner wire, we increase the cross-sectional density of atoms in the wire, thus the electrons in the current collide more with the atoms of the wire, and the resistance increases.

Answer

a) increasing its temperature

c) using a longer wire

g) using a thinner wire

Explanation

a) increasing its temperature

Increasing the temperature of a conductor increases the kinetic energy of the free electrons making them to collide as they travel. This prevents the free movement of electrons that act as charge carriers.

c) using a longer wire

The longer the wire the more resistance it has. Resitance of a wire is directly proportional to its length.

g) using a thinner wire

A thinner wire has few electrons hence more resistance.