Question

How does bimetallic strip function when heated?

Answer 1

A bimetallic strip works on the principle of **thermal expansion**, where different metals expand at different rates when heated. A bimetallic strip consists of two metals with distinct coefficients of thermal expansion, typically brass (which expands more) and steel (which expands less), bonded together.

Here’s how it functions:

1. **Heating**: When the bimetallic strip is heated, the metal with the higher coefficient of expansion (brass) expands more than the metal with the lower coefficient (steel).
  
2. **Bending**: Due to the unequal expansion, the strip bends toward the side of the metal that expands less (steel in this case). This bending occurs because the strip is constrained by the two metals being joined, forcing a curvature.

3. **Application**: The bending movement can be used in various applications like:
   - **Thermostats**: The strip bends with temperature changes to make or break an electrical contact, controlling heating and cooling systems.
   - **Circuit breakers**: When the strip bends due to overheating, it opens a circuit, preventing electrical overloads.

The amount of bending increases with temperature, making it a reliable tool for temperature-based control.

Answer 2

Are you asking about a specific application of bimetallic strips, such as in thermostats, or are you interested in the general principle behind their operation?