Cells EMF Internal Resistance: Cells, Electromagnetic Fields (EMF), and Internal Resistance are related concepts in physics and electrical engineering.

A cell is a device that generates electrical energy through a chemical reaction. There are different types of cells, such as primary cells (disposable) and secondary cells (rechargeable).

Electromagnetic Fields (EMF) are fields of energy that are created by moving electric charges. They are produced by natural sources like the Earth’s magnetic field, and also by man-made sources such as power lines, electrical appliances, and cell phones.

Internal Resistance is the resistance within a cell or battery that opposes the flow of electric current. It is caused by the resistance of the materials making up the cell and by the internal resistance of the chemical reaction. This internal resistance can affect the performance of a cell or battery by reducing the voltage and limiting the amount of current that can be supplied.

Cells EMF Internal Resistance

Electric Cell – Electromotive Force (EMF)

The electric cell can be defined as an external source that creates a potential difference between two points A and B in the circuit. The cell will create a potential difference between the terminals A and B that is equal to the EMF (Electromotive force) of the cell when it is not connected to the external circuit or we can say when the circuit is an open circuit without any flow of current. The work done in driving a unit charge across the terminals is called electromotive force. EMF is not a force, it is the potential difference. The unit of EMF is volt.

The electromotive force is denoted as ε.

ε = W/q = V_AB

here,

W is the work done

q is the unit charge

V_AB is the potential difference across terminals A and B

Internal Resistance

Internal resistance is the resistance to the flow of electrical current within a device, such as a battery, a cell, or an electrical circuit. It arises from several sources, including the resistance of the materials making up the device, as well as resistance due to internal processes, such as chemical reactions in a battery.

The internal resistance of a device can have an impact on its performance. For example, in a battery, the internal resistance can cause a drop in voltage, which can limit the amount of current that can be supplied to an external circuit. In an electrical circuit, the internal resistance can cause a loss of energy as heat, reducing the efficiency of the circuit.

Measuring and reducing internal resistance is an important aspect of designing and optimizing electrical devices, especially in applications where high current or high power is required, such as in batteries for electric vehicles or in power supplies for electronic devices. Techniques used to reduce internal resistance include using materials with low resistance, such as copper, and improving the internal structure of the device to minimize the distance that the current must travel.

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By Team Learning Mantras