Galvano meter

Definition.

 It is an electrical instrument which is used to detect the passage or flow of current.

 Principle:

  The working of a galvanometer depends upone the torque exerted on a coil suspended in a
current is passed through the coil.galvanometer,s picture is given below

                                        
due to the action of this torque, the coil rotates and galvanometer shows reading and thus 
it detects the current.
                                               

                                                    
 Construction.
  Moving coil galvanometer consists of a rectangular coil C suspended between the concave 
   shaped poles N and S of U - shaped magnet by means of a fine metallic wire F which carries a
  plane mirror M. the coil is used of insulated (enameled) copper wire wound on a rectangular frame
  of some non-magnetic material. the other terminal of coil is connected to a loosely wound spiral E
   which acts as the second current lead.
   the pole pieces of the magnetic are made concave and a soft iron cylinder piece B is fixed between
   the poles.it makes the field redial and stronger near the coil.