To observe and explain the effect of heating on a bi-metallic strip, a bi-metallic strip is made up of two strips or bars of different metals such as iron and brass, having same dimensions placed one over another lengthwise and riveted at their ends. Different solids expand or contract differently for the same change in temperature. At room temperature, the bi-metallic strip is straight. Madam, how can we observe the effect of heating on a bi-metallic strip? On heating, the bi-metallic strip bends with brass portion on the outer side. It means brass expands more than iron on heating. Let's do an experiment to observe the effect of heating on a bi-metallic strip. Our aim here is to observe and explain the effect of heating on a bi-metallic strip. The materials required are a bi-metallic strip of iron and brass, heating arrangement, a board with clamps screw on one side and vertical scale on the other side. Thermometer procedure. First of all, place the bi-metallic strip on a horizontal surface to check that the strip is straight or not in the beginning. Now suspend the bi-metallic strip in a clamp stand from its one end, keeping the brass strip on the upper side. Heat the bi-metallic strip with the help of heating arrangement, burner and observe the bending of the strip. The free end of the bi-metallic strip is bent in the form of an arc. The metal which forms the upper part has a larger coefficient of linear expansion. Remove the heating arrangement and place the bi-metallic strip in ice for some time. It is observed that the strip becomes straight. Observations. With increase in temperature, the bi-metallic strip bends more. Brass strip expands more than the iron strip and therefore brass forms out of the bend strip. Result. Brass metal expands more than iron for the same temperature change. Precautions. The length of bi-metallic strip should be large as compared to its width or thickness. The bi-metallic strip must be riveted at a large number of places. One end of the bi-metallic must be clamped rigidly. Heating of the whole bi-metallic strip should be uniform. Sources of error, the rivets may be loose. Heating of bi-metallic strip may not be uniform.