HOW INTERNAL RESISTANCE OF A LECHLANCHE CELL IS CALCULATED USING A POTENTIOMETER ?

INTERNAL RESISTANCE OF A LECHLANCHE CELL :

CIRCUIT DIAGRAM:

• AB          -Potentiometer
• Bt            -Battery EliK₁       
•  K1                     -Plug key in the primary circuit
• K₂            -Plug key in the   secondary circuit
• Rh           -Rheostat
• L (or) E   -Lechlanche cell
• H.R         -High Resistance
• G            - Galvanometer
• R            -Resistance box
• J₁, J₂      -Pencil Jockey positions

EXPERIMENTAL SET UP:

SIMPLE CIRCUIT DIAGRAM:

PROCEDURE:

• The circuit associations and the test set up are made as displayed previously.

• In the open circuit,when resistance is excluded (not included), the emf of the cell is deterimned by taking note of the balncing length.That is l1

• In the shut(closed) circuit, when the resistance is incorporated the balncing length is to be noted. That is  l2

• The trial is rehashed for various values of R and the readings are organized.

• Utilizing the equation the internal resistance of the given cell can be determined.

TABULAR COLUMN:

CALCULATION:

RESULT:

The internal resistance of the given  primary cell (Lechlanche cell)   =  7.16 Ohms

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