A Level Physics Practice Exam

How does temperature affect the resistance of metals?

1. The resistance decreases due to less vibration of metal ions

2. The resistance remains constant regardless of temperature

3. The resistance increases due to greater vibration of metal ions

4. The resistance increases due to reduced electron flow

The correct answer is: The resistance increases due to greater vibration of metal ions

The relationship between temperature and the resistance of metals is grounded in the behavior of metal atoms and the electrons that move through them when heat is applied. As the temperature rises, metal ions in the metallic lattice vibrate more vigorously. This increased vibration leads to a higher likelihood of collisions between conduction electrons (the electrons that facilitate electrical current) and these vibrating ions. Because of these collisions, the effective flow of electrons is hindered, resulting in a higher resistance. Essentially, as the atomic motion increases with temperature, the path for conduction becomes less straightforward for the electrical charge carriers. This is a characteristic behavior for metals in general, where the resistance increases as temperature increases. In contrast, other options either misrepresent the relationship between temperature and resistance or apply concepts that are not relevant in this context, such as suggesting that resistance remains constant or that it decreases due to lesser vibrations, which contradicts the fundamental principles of metallic conduction.