This video explains concept of Thermal Expansion. The fundamental has been very well explained through 3D models and animation by our Master Teacher. It explains what is thermal expansion, what are the types / classes of thermal expansion - Linear Expansion, Superficial Expansion and cubicle expansion. It tells about how thermal expansion occurs in railway tracks, bridges, and bimetallic strips. Application of thermal expansion in Automatic Fire Alarm system through bimetallic strips is elaborated well through a 3D working model. This is suitable for students of class sixth (6th), class seventh (7th), class eight (8th) and class ninth (9th). The syllabus covered is from the books like Concise Physics, Living Science, NCERT etc.