Difference between EMF by direct method and EMF by combination method
EMF is nothing but an electromotive force and it is denoted by E (E= W/Q) . Electromotive force is simply defined as the electric potential produced by either electrochemical cell or batteries or by changing the magnetic fields the electrical action produced by a non-electrical source. Batteries or Generators provides an electromotive force by converting other forms of energy into electrical energy. The fun fact about the electromotive force is that it is not actually a force. It is commonly measured in units of volt. The comparison of EMF by direct method and EMF by combination method is done using potentiomete and galvanometer. In direct method we find the EMF of individual cell. In the combination method we find EMF of two cell by two combination i.e by EMF which assist each other and EMF which oppose each other. In this comparison the voltage of the main battery should be greater than the EMF of two cell.
EMF by direct method |
EMF by combination method |
1) The comparison is said to be direct because direct method we find the EMF of individual cell.
2) In the direct method we use two way key. 3) The direct method is also know as individual method. 4) The comparison of EMF is given by E1/E2 = l1/l2. |
1) The comparison is said to be combination because In the combination method we find EMF of two cell by two combination i.e. by EMF which assist each other and EMF which oppose each other.
2) In the combination method we use four way key. 3) The combination method is also know as sum and difference method. 4) The comparison of EMF is given by E1/E2 = l1+l2/ L1-l2. |