Cells in Series and Parallel

As we know the most frequently used method to connect electrical components is Series Connection and Parallel Connection. Since the cell is an important part of an electric circuit. To know more about Cells, Series Connection and parallel Connection explore the article!

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Cells

Cells generate electricity and also derives chemical reactions.  One or more electrochemical cells are batteries. Every cell has two terminals namely:

1. Anode: Anode is the terminal from where the current flows in from out i.e. it provides an incoming channel for the current to enter the circuit or the device.
2. Cathode: Cathode is the terminal from where the current flows out i.e. it provides an outgoing current flow from the circuit or the device.

Learn more about Electric Charge here in detail

There are two simplest ways for cell connectivity  are as follows:

1. Series Connection: Series connection is the connectivity of the components in a sequential array of components.
2. Parallel Connection: Parallel connection is the connectivity of the components alongside to other components.

Cells in Series Connection

In series, cells are joined end to end so that the same current flows through each cell.  In case if the cells are connected in series the emf of the battery is connected to the sum of the emf of the individual cells. Suppose we have multiple cells and they are arranged in such a way that the positive terminal of one cell is connected to the negative terminal of the another and then again the negative terminal is connected to the positive terminal and so on, then we can that the cell is connected in series.

Browse more Topics under Current Electricity

• Electric Current
• Ohm’s Law
• Electrical Energy and Power
• Resistivity of Various Materials
• Temperature Dependence of Resistivity
• Drift of Electrons and the Origin of Resistivity
• Combination of Resistors – Series and Parallel
• Atmospheric Electricity and Kirchhoff’s Law
• Wheatstone Bridge, Meter Bridge and Potentiometer
• Cells, EMF, Internal Resistance

Equivalent EMF/Resistance of Cells in Series

If E is the overall emf of the battery combined with n number cells and E_1, E_2, E₃ , E_n are the emfs of individual cells.

Then   E₁ + E_2 +  E₃ + …….E_n 

Similarly, if r₁, r₂, r₃, r_n are the internal resistances of individual cells, then the internal resistance of the battery will be equal to the sum of the internal resistance of the individual cells i.e.

r = r₁ + r₂+  r₃ +  r_n

Cells in Parallel Connection

Cells are in parallel combination if the current is divided among various cells. In a parallel combination, all the positive terminal are connected together and all the negative terminal are connected together.

Equivalent EMF/Resistance of Cells in Parallel

If emf of each cell is identical, then the emf of the battery combined with n numbers of cells connected in parallel is equal to the emf of each cell. The resultant internal resistance of the combination is,

r =  \(( \frac{1}{r_1} \) + \( \frac{1}{r_2 } \) +  \( \frac{1}{ r_3} \) +……..  \( \frac{1}{r_n} \) )^-1

Equivalent EMF/Resistance of Cells in Series and Parallel

Assume the emf of each cell is E and internal resistance of each cell is r. As n  numbers of cells are connected in each series, the emf of each series, as well as the battery, will be nE.  The equivalent resistance of the series is nr. As, m the number of series connected in parallel equivalent internal resistance of that series and parallel battery is nr/m.

Solved Questions For You

Q. The internal resistance of a cell of emf 1.5 V, if it can deliver a maximum current of 3 A is,

1. 0.5 Ω
2. 4.5 Ω
3. 2 Ω
4. 1  Ω

Solution: A. For maximum amount, load resistance = 0

⇒ E = Ir

r = \( \frac{E}{I} \)

= \( \frac{1.5}{3} \)

= 0.5 Ω

Q.2 For a given cell, its terminal voltage depends on

1. External resistance, Internal Resistance
2. External resistance
3. Internal Resistance
4. None of these

Solution: A. Inside the cell, the energy is put into the circuit by the cell, but some of this energy is out by the internal resistor. So the potential difference available to the rest of the circuit is the emf minus the potential difference lost inside the cell.