How to calculate electromotive force?

Electromotive force also known as EMF can be explained as the energy supplied by a battery or a cell per coulomb of charge that passes through the battery. The emf is measured in measured in volts. The formula to calculate electromotive force is given below: ε = Electromotive force [volts] I = Current [amps] R = Resistance of load in circuit [ohms]

How do you measure electromotive force in a cell?

The electromotive force (EMF) of a cell is the amount of energy transferred per coulomb of charge. This is given in the equation: \varepsilon = \dfrac {E} {Q} EMF can be directly measured in a circuit by placing a voltmeter in parallel across the terminals of the battery whilst not connected to a circuit.

How do you calculate the electromotive force of an electrochemical cell?

The electromotive force of the electrochemical cell can be calculated using the equation: EMFcell [V] = Ecathode [V] - Eanode [V] where E cathode is the potential of the cathode (in volts) and E anode is the potential of the anode (in volts). Remember that in a cell, the potential of the cathode is higher than the potential of the anode.

What determines EMF of a battery?

The combination of chemicals and the makeup of the terminals in a battery determine its emf. The lead acid battery used in cars and other vehicles is one of the most common combinations of chemicals. Figure 10.2.3 shows a single cell (one of six) of this battery.

Why does electric potential increase the emf of a battery?

The electric potential increases the emf of the battery due to the chemical reactions doing work on the charges. There is a decrease in the electric potential in the battery due to the internal resistance. The potential decreases due to the internal resistance − Ir, making the terminal voltage of the battery equal to (ϵ − Ir).

What is EMF & internal resistance of batteries & cells?

It is the role of the power source to supply the circuit and its components with energy. If the power source is a battery or a cell, chemical energy is converted to electrical energy. However, this process is not always 100 percent efficient. In this section we look into the Electromotive Force (EMF) and internal resistance of batteries and cells.