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INTRODUCTION

Physical phenomena associated with the presence and flow of electric charge is known as electricity. Electricity and electrical phenomenon have a lot of applications in our day to day life and they also gives a wide variety of well-known effects, such as lightning, static electricity, electromagnetic induction and the flow of electrical current.

  • Electricity occurs due to several types :
    1. Electric charge: a property of some subatomic particles, which determines their electromagnetic interactions.
    2. Electric current: a movement or flow of electrically charged particles, typically measured in amperes.
    3. Electric field: an especially simple type of electromagnetic field produced by an electric charge even when it is not moving (i.e., there is no electric current). The electric field produces a force on other charges in its vicinity. Moving charges additionally produce a magnetic field.
    4. Electric potential: the capacity of an electric field to do work on an electric charge, typically measured in volts.
  • In this chapter we will study about electricity.

When current flows through a conductor, heat energy is generated in the conductor. The heating effect of an electric current depends on three factors:

  • The resistance, R of the conductor. A higher resistance produces more heat.
  • The time, t for which current flows. The longer the time the larger the amount of heat produced
  • The amount of current, I. the higher the current the larger the amount of heat generated.

Hence the heating effect produced by an electric current, I through a conductor of resistance, R for a time, t is given by H = I2Rt. This equation is called the Joule’s equation of electrical heating.