differentiate between Emf and Potential difference Pd.
THere is not much difference in actual usage. Historically, emf was used on sources to indicate the rate at which energy could be extracted, and potential difference was used to indicate the amount of potential energy that could be released between two points. As used now, there is insignificant difference.
To differentiate between electromotive force (EMF) and potential difference (PD), we need to understand their definitions and characteristics.
1. Electromotive Force (EMF):
- Definition: EMF refers to the energy per unit charge supplied by a source (e.g., a battery or a power supply) in order to maintain a steady electric current in a circuit.
- Symbol: EMF is denoted by the symbol E or ε.
- Measurement unit: EMF is measured in volts (V).
- Characteristics:
- EMF represents the total voltage generated by a source, including the energy used to overcome any internal resistance within the source.
- It is independent of the presence or absence of a circuit, meaning it is the potential difference across the terminals of a source when no current is flowing.
- EMF can supply energy to a circuit, even if it is not actually used by the circuit.
2. Potential Difference (PD):
- Definition: PD refers to the energy per unit charge that is transferred as a charge moves between two points in an electric circuit.
- Symbol: PD is denoted by the symbol V or ΔV.
- Measurement unit: PD is measured in volts (V).
- Characteristics:
- PD represents the voltage difference between two points in a circuit, which causes the electric charge to flow from higher potential to lower potential.
- It depends on the presence of a closed circuit, as it is the voltage drop across a load or between any two points in a circuit.
- PD is responsible for the actual work done by the electric charge as it flows through the circuit.
In summary, EMF refers to the energy per unit charge supplied by a source, whereas PD refers to the energy per unit charge transferred between two points in a circuit. EMF is independent of the circuit and represents the total voltage generated, while PD depends on the circuit and causes the charge to flow from higher to lower potential.