A voltmeter connected across the terminal of a battery measures the potential difference. How is it different from emf
Answers
Answer:
Explanation:
When you measure the potential difference across (or between) the terminals of a battery that is not in a complete circuit you are measuring the emf of the battery. The voltmeter may also be used to measure the voltage across a resistor or any other component of a circuit but must be connected in parallel. When a circuit is connected and complete, charge can move through the circuit. Charge will not move unless there is a reason, a force to drive it round the circuit. Think of it as though charge is at rest and something has to push it along. This means that work needs to be done to make charge move. A force acts on the charges, doing work, to make them move. The force is provided by the battery in the circuit. A battery has the potential to drive charge round a closed circuit, the battery has potential energy that can be converted into electrical energy by doing work on the charge in the circuit to make it move. Actually voltmeter measures the PD while emf provides actually emf is the energy supplied to unit positive charge and emf always exist whether it is connected in circuit or not