The main difference between an ammeter and a galvanometer is that the ammeter indicates only the magnitude of the current, while the galvanometer indicates the direction and magnitude of the current.
A galvanometer changes the current with the help of a moving coil alternating between permanent magnets and the coil rotates due to the current A galvanometer can be converted into an ammeter by connecting the resistors of an electric circuit in parallel. When a resistance is connected in series with it, it can be used as a voltmeter.
What is a Galvanometer?
A galvanometer is an electrical measuring device used to measure current strength and direction in an electrical circuit. A typical galvanometer consists of a moving coil, a permanent magnet, a metal base, a non-magnetic frame, a hanging wire, and a spring.
A coil is placed between the two poles of a permanent magnet. When an electric current flows through a coil, it creates a magnetic field around the coil that matches the magnetic field of a permanent magnet. The interaction of the two magnetic fields exerts a force on the coil and therefore the coil begins to rotate.
Connected to the moving coil is an indicator whose deflection indicates the magnitude and direction of the current. In the case of a galvanometer, the deflection of the pointer is directly proportional to the strength of the current flowing in the circuit.
A galvanometer can only be used to measure direct current (DC). Galvanometers are often used in bridges and potentiometers to determine zero current.
What is an Ammeter?
An ammeter, also called an ammeter, is a measuring device that measures the strength (or magnitude) of current flowing in a circuit. An ammeter can be used to measure both direct current (DC) and alternating current (AC).
An ammeter only measures the magnitude of the current and not the direction. The accuracy of the ammeter is much higher than that of the galvanometer. The ammeter can be an electronic device or a digital ammeter. For a good ammeter, the internal resistance should be zero.
Difference between Ammeter and Galvanometer
| Ammeter | Galvanometer |
| It is a device used to determine the magnitude of current flowing in a circuit. | It is a device used to detect the strength and direction of a small current present in the circuit. |
| It works with or without the presence of the magnetic field. | It works due to the presence of the magnetic field. |
| It measures both alternating and direct current. | It measures only direct current. |
| It is less sensitive. | It is more sensitive. |
| It is more accurate. | It is less accurate. |
| It could be a mechanical or electronic device. | It is a mechanical device. |
| It is used in an electrical circuit. | It is used in bridges and potentiometers. |
