The length of a brass rod is found to be smaller on a hot summer day than on a cold winter day as measured by the same aluminium scale do you conclude that brass shrinks on heating?

Answer 1

Yes it has!

Answer 2

No, the brass rod could be expanding or contracting due to changes in temperature, but it does not necessarily mean that brass shrinks on heating. Temperature changes can cause thermal expansion or contraction in materials, including brass. To determine if brass specifically shrinks on heating, a controlled experiment measuring thermal expansion coefficients would be needed.