#VishnuPhysics #potentiometer
Potentiometer consists of long wire with uniform cross-section.
Instead of long wire small pieces of wire is taken and each of those pieces are fixed parallel to each other on a platform.
Wires are connected by a copper strip. As there are 6 pieces of wire therefore the length of the wire =6m.
There is a driving circuit which consists of battery, key and rheostat.
This is the circuit which will provide the current, and this current flow through this longwire.
Galvanometer
One end of galvanometer is connected to the point AB on the circuit with the help of jockey, and other end is left free.
Terminals of potentiometer(End points)
These are the points between which the potential difference needs to be measured.
One endpoint = free end of the galvanometer and other endpoint = the one end of wire A of the circuit.
End A is at higher potential and end B is at lower potential.
Graduated scale for measurement.
Working:-
To find out potential difference between 2 points(a and b) of the circuit.
Point A is connected to (a)and point C is connected to (b).
Assume all the connecting wires have 0 resistances.
Potential at point ‘a’= Potential at point ‘A’.
Similarly potential at ‘b’=Potential at some point before B.
While Sliding the jockey there will be a point where galvanometer shows deflection equal to 0.Let that point be P.
Therefore, potential at point ‘b’=potential at point ‘P’.
Let AB=L(length) and AP=l.At L=value of deflection is 0.