Custom Search

What is electromotive force?

 We use radio, television, refrigerators tube light etc in our home appliance. To operate these appliances we need electric energy. There are many kinds of sources of electrical energy like generator, electric cell or battery.

Let us consider a torch light. There are two or there dry cell in series combination is called battery. Copper plate and a small bulb connection with the battery. The source of energy in the torch light is battery because it supplies current here. Electric energy transfers from the battery to the bulb and the filament of the bulb heated and radiates light.

 emf electromotive force

Due to chemical reaction in the battery charges travel one terminal to another terminal. So, one terminal becomes positively charged and one is negatively charged.

Having the positive and negative charge in the two terminals of the cells a potential difference creates between two terminals.

 The maximum potential difference that exists between the terminals of the cell when it is disconnected from the external circuit is called electromotive force emf of the cell.

electromotive force emf

If we connect an external resistance R which is small r, it remains inside the cell. The current will continue to the R until disconnection of the circuit or the damage of cell. It can be said that cell is the driving force which maintains current flow in the circuit.

So, another definition of the electromotive force is “The driving force which keeps or maintains the flow or current in the circuit is called electromotive force. The short name of electro motive force is emf. It is denoted by E.

Unit of emf: The unit of emf electromotive force is volt (V) or Joule/ Coulomb (J/C).

Share this Story
  • What is electromotive force?

     We use radio, television, refrigerators tube light etc in our home appliance. To operate these appliances we need electric energy. There ...
Load More Related Articles
  • Combination of Cells

    Why cell combination needed? A cell is an electrical element which produces current and a battery is a set of some ...
  • Best Breadboard

    Breadboard is a basic instrument for electrical and electronic engineering or telecommunication engineering or physics students or teacher or researcher. Teacher, ...
  • Top 7 Best Multimeters: Reviews Based on Performance

    Important factors are before buying multimeter You have to consider some factors before buying a multimeter Budget Functions Safety feature Accuracy ...
  • How To Read Resistor Color Code

    Resistor and Resistance Resistance is a property of conductor. Resistivity depends upon conductor to conductor. Some have less resistivity which is ...
  • Electrical Ohm’s Law

    In 1826 famous German scientist Gorge Simon Ohm invented a relation between voltage and current. He expressed the relation in a ...
  • Force on a Current Carrying Conductor in a Magnetic Field

    We know moving charge experiences a force due to magnetic field. Magnetic field creates force into conductor passing current through it. ...
Load More By Md Ebrahim Shah
  • Combination of Cells

    Why cell combination needed? A cell is an electrical element which produces current and a battery is a set of some ...
  • How To Read Resistor Color Code

    Resistor and Resistance Resistance is a property of conductor. Resistivity depends upon conductor to conductor. Some have less resistivity which is ...
  • Electrical Ohm’s Law

    In 1826 famous German scientist Gorge Simon Ohm invented a relation between voltage and current. He expressed the relation in a ...
  • Force on a Current Carrying Conductor in a Magnetic Field

    We know moving charge experiences a force due to magnetic field. Magnetic field creates force into conductor passing current through it. ...
  • Wheatstone Bridge

    Wheatstone bridge is a bridge where four resistances are used. First and second resistance are connected in series; third and fourth ...
  • Biot Savart Law

    To understand completely Biot Savart Law some important rules or laws should be known are Maxwell cork screw Law, Fleming’s right ...
Load More In Physics

Check Also

Combination of Cells

Why cell combination needed? A cell is an ...

© Copyright 2009-2017, All Rights Reserved.