Difference Between Ammeter and Voltmeter (With Table)

Physics is always a confusing subject. Every object and thing has different types of measurement and standards. It is complex to keep in mind. But it becomes easy when we make a comparative study and know the differences. Every description has specific definitions, and it is easy to remember the formulas once we read the definitions.

Ammeter vs Voltmeter

The difference Between Ammeter and Voltmeter is their usage. The ammeter is used to measure electric current. The voltmeter is used to measure the electrical potential difference. The connection in the circuit is different on both. The ammeter is connected in series, whereas the voltmeter is connected in parallel. But both are used to measure the electricity. The ammeter measures the flow of the current. The voltmeter measures the voltage of the current.

The ampere meter is shortend to ammeter. It is a measuring instrument used to measure the electricity by connecting to the series in the circuit. The current measured are denoted in Amperes with the symbol of A. Low resistance cannot cause voltage drop is the concept behind the ammeter. The milliampere and microampere are used to measure small amounts of currents. Due to the earth’s magnetic field, the ammeter are used only in the laboratories in the early days. In the circuit, the ammeter is denoted by the symbol A.

The voltmeter is a device to measure the current by voltage. The voltmeter is connected in parallel in the circuit. It is usually used to measure the electrical potential difference. Unlike ammeter, voltmeter has high resistance that negligible the current is the concept behind the voltmeter. From the galvanometer and series resistor, the pointer in the voltmeter measures the voltage. By using the amplifiers you can measure tiny voltages in microvolts. In recent days, digital voltmeters are used widely, which show the numerical display.

Comparison Table Between Ammeter and Voltmeter

Parameters of comparisonAmmeterVoltmeter
DefinitionAmmeter used to measure the currentVoltmeter used to measure the voltage
SymbolAmmeter is denoted by AThe voltmeter is denoted by V
Resistance rangeAmmeter has low resistanceThe voltmeter has high resistance
Changing the rangeAmmeter does not allow to change the rangeVoltmeter allows you to change the range
ConnectionAmmeter is connected in seriesThe voltmeter is connected in parallel

What is Ammeter?

Ammeter is a measuring instrument used to measure the current by connecting in series in the circuit. It can measure both the direct and alternating current in the circuit. The ammeter measures the current in amperes. The microcurrent is denoted by microamperes. The symbol of the ammeter is A. The ammeter has low resistance. It is connected in series with a galvanometer to measure the current. In simple, the ammeter is a device or instrument which measures the current.

Depending on the principles and accuracies, the ammeter’s value gets changed. From 0.1 to 2.0 accuracy, the current was measured through D’Arsonal movement by the ammeter. The ammeter is also present in electrodynamic motors. The electrodynamic motor ammeter has a fixed coil and moving coil. The electrodynamic ammeter measures the current from 0,1 to 0.25 accuracies. The thermal ammeter measures from 0.5 to 3 accuracies.

A short circuit is produced, when the ammeter is connected in parallel in the circuit. The resistance will be zero for an ideal ammeter and it is impossible to produce an ideal ammeter. If you are using an ammeter, you must aware of the shunt resistance. The shunt resistance will break the entire circuit. Multi-range ammeter is available in recent days. Digital ammeter is the popular one which causes no wastage.

What is Voltmeter?

The voltmeter is a measuring instrument used to measure the voltage by connecting in parallel to the circuit. If you connect the voltmeter in series with the circuit then a short circuit will be caused. The voltmeter is created by connecting a high resistance with a galvanometer in parallel in the circuit. The voltmeter is available in a wide range of models in recent days. Any changes in the voltage will be shown in the display of the voltmeter.

The general purpose voltmeters have a range from small to several thousand. Like an ammeter, the voltmeter is also available in digital. The digital voltmeters have a high level of accuracy. The laboratory voltmeters have always special capability. It measures almost per million things. The western cell is a standard usage of a voltmeter for precision work. The western cell has perfect voltage measurement, which makes a better electronic circuit.

There are three types of voltmeters are available in recent years. They are an analog voltmeter, amplified voltmeter, and digital voltmeter. All the voltmeters work behind a similar concept. But the production of the three voltmeters is different from one other. On the three, digital voltmeters are preferred by many people.

Main Differences Between Ammeter and Voltmeter

  1. The flow of current is measured by an ammeter, and the voltage of the current is measured by a voltmeter.
  2. The accuracy of measurement is more in the ammeter when compared to the voltmeter.
  3. The resistance is zero in the ideal ammeter, and the resistance is infinity in the ideal voltmeter, but both are impossible in reality.
  4. In the circuit, the ammeter is denoted by A and the voltmeter is denoted by V.
  5. By connecting small resistance in with galvanometer in parallel the ammeter is created, and by connecting high resistance in series with galvanometer voltmeter is created.


Both the ammeter and voltmeter have a unique purpose in the circuit. An ammeter is used to measure the current and the voltmeter is used to measure the voltage. The ammeter is created by connecting a low resistance in series with a galvanometer whereas the voltmeter is created by connecting a high resistance in parallel with a galvanometer. Both have different physical properties and are used to measure electricity.


  1. https://www.degruyter.com/document/doi/10.1515/9780691218120-012/html
  2. https://ieeexplore.ieee.org/abstract/document/7973559/
2D vs 3D