What happens to the resistance of a material if the temperature increases?

• A. Resistance decreases
• B. Resistance increases
• C. Resistance remains unchanged
• D. Resistance fluctuates

Answer: (B)

When the temperature of a material increases, its resistance typically increases as well. This phenomenon can be attributed to the behavior of the atoms and electrons within the material. As the temperature rises, the atoms in the material vibrate more intensely. This increased vibration causes more collisions between the free electrons, which are responsible for conducting electricity, and the vibrating atoms.

As a result of these increased collisions, the electrons face more resistance to their flow, leading to a higher overall resistance of the material. This principle is particularly evident in conductors, such as copper or aluminum, where resistance varies significantly with temperature. In contrast, some materials known as semiconductors can behave differently under increased temperature, which is crucial for understanding their applications in electronics, but for many common conductive materials, resistance indeed increases with temperature.