moving-coil galvanometer
A student observes the needle of a moving-coil galvanometer during a physics experiment.
Noun: A moving-coil galvanometer is a sensitive instrument for detecting or measuring small electric currents. Its operation is based on the force exerted on a movable coil, which carries the current, when it is suspended within a magnetic field. The deflection of the coil is proportional to the current passing through it.
This term is used specifically in the context of physics and electrical engineering to describe a classic type of analog measuring instrument. - It functions as the core sensing mechanism in many analog ammeters and voltmeters. - Its design is fundamental for understanding electromagnetic principles.
- The laboratory demonstration used a moving-coil galvanometer to show the magnetic effect of an electric current.
- To measure the tiny current from the photocell, a sensitive moving-coil galvanometer was employed.
- The design of the moving-coil galvanometer, with its coil and permanent magnet, makes it a precise tool for DC measurements.
- Historical Context: The moving-coil galvanometer, often associated with the D'Arsonval/Weston type, represented a major advancement in electrical instrumentation due to its linear scale and sensitivity.
- Underlying Principle: The operation relies on the motor principle: a torque acts on a current-carrying coil in a magnetic field, causing it to rotate against a restoring spring.
- Galvanometer (n): The general term for any instrument that detects electric current by its magnetic effects.
- Ballistic galvanometer (n): A type of galvanometer designed to measure the total quantity of electricity (charge) in a transient current pulse, often using a moving-coil design with minimal damping.
- Ammeter (n): A current-measuring instrument that often uses a moving-coil galvanometer as its core movement, with added shunts to handle larger currents.
- Voltmeter (n): An instrument for measuring electrical potential difference, frequently constructed by connecting a high resistance in series with a moving-coil galvanometer.
- D'Arsonval galvanometer
- Weston galvanometer
- Permanent-magnet moving-coil (PMMC) instrument
- "Coil deflection": The angular movement of the coil in a moving-coil galvanometer, which indicates the current strength.
- "Magnetic torque": The rotational force that causes the coil to move, fundamental to the instrument's operation.
- "Analog meter movement": A common description for the moving-coil galvanometer mechanism when used as the display component in a meter.
A student observes the needle of a moving-coil galvanometer during a physics experiment.
- a galvanometer that is operated by the force exerted by an electric current flowing in a movable coil suspended in a magnetic field