Month: June 2011

  • Frictional Electricity

    Frictional Electricity: The word electricity is derived from the Greek word ‘electron’ which means amber.  In the sixth century BC, a Greek philosopher Thales found that when a piece of amber (a kind of resin) is rubbed with fur, it acquires a remarkable property; it attracts small pieces of leaves, cork or dust. Today, we…

  • Physics XI | Frame of Reference

    Frame of Reference: Suppose someone asked you a question “How far is India?” your reaction would be “from where?” Then the person who asked you the question would tell, from here or from United States. So in kinematics some reference is very necessary to measure distances. Suppose, you are sitting inside a stationary train. At…