ADVANTAGES
The generation of A.C. is cheaper than that of D.C.
A.C. machines are simple , robust and do mot require much attention for their repairs and maintainance during their use.
Wide range of voltages are obtained by the use of transformer.
Wave velocity in a continuous system
Any system whose particle motion are governed by classical wave equation is a system in which harmonic waves of any wavelength can travel with the speed v
The value of v depends on the elastic and inertial properties of the system under consideration.
(1) Transverse wave on a stretched string
Displacement of the string is governed by the equation
Crystals
Many materials like carbon can exist in various forms for example it can exist as diamond in solid form and graphite is also one form of carbon and clearly dimond and graphite have different mechanical, thermal, optical and electrical properties. These properties of different forms of carbon can be understood in terms of carbon atoms in the solid structure.