Internal resistance is the electrical resistance inside batteries and power supplies that can limit the potential difference that can be supplied to an external load.
It is the resistance offered by the electrolyte of a cell to the flow of current between its electrodes.
INTERNAL RESISTANCE-IMAGE
Internal resistance of a cell is the resistance offered by the electrode and electrolyte which oppose the current flow inside the cell. The higher the internal resistance, the less current the battery is capable of giving.
A freshly prepared cell has low internal resistance and this increases with ageing. Batteries that have high internal resistance will take more time to fully charge.
INTERNAL RESISTANCE VALUE OF A DRY CELL AND LECLANCHE CELL
High resistances cause the battery to heat up excessively and voltage output to drop under high demand. The internal resistance of a dry cell varies from about 0.5 to 1.0 ohms.The internal resistance of a Leclanche cell is about 5 to 10 ohms.
PRACTICAL IMPORTANCE OF INTERNAL RESISTANCE OF A CELL
Internal resistance is important because it affects the battery’s efficiency, performance, and lifespan. Higher internal resistance leads to more energy loss as heat.
INTERNAL RESISTANCE – FORMULA
EMF AND POTENTIAL DIFFERENCE:
DIFFERENCE BETWEEN EMF & POTENTIAL DIFFERENCE
HOW TO CALCULATE INTERNAL RESISTANCE OF A CELL/BATTERY?
HOW TO CALCULATE INTERNAL RESISTANCE OF A PRIMARY CELL USING POTENTIOMETER?
CIRCUIT DIAGRAM
EXPERIMENTAL SETUP
FORMULA
TABULAR COLUMN
Internal resistance of a cell/battery is the resistance offered by the electrode and electrolyte which oppose the current flow inside the cell. The higher the internal resistance, the less current the battery is capable of giving.
A cell’s internal resistance influences its ability to deliver current to a load. When compared to used cells, freshly prepared cells have lower internal resistance.Did you measure the internal resistance of a cell in your laboratory?
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