This book describes in detail measurements and errors. Each measurement is prone to errors. How these errors can be estimated and statistical parameters are calculated have been discussed. In the chapter on Optics, from the description of lenses and various kinds of aberrations, a detailed discussion about the interference, coherence and diffraction phenomena has been given.
Along with fiber optics a chapter has been devoted to understand, how various kinds of elasticities are developed in an elastic material and how they are related with one another. As the phenomenon of interference is not only found in the electromagnetic waves, but in the mechanical waves as well, a complete description about the waves and oscillations and propagation of sound has been included.