Correct Answer - Option 3 : Electrostatic type
Moving-Iron Instruments (MI):
- Moving-iron instruments are generally used to measure alternating voltages and currents.
Permanent Magnet Moving Coil (PMMC):
- A Permanent Magnet Moving Coil (PMMC) meter also known as a D'Arsonval meter or galvanometer is an instrument that allows you to measure the current through a coil by observing the coil's angular deflection in a uniform magnetic field.
Electrostatic Instrument
- The instrument whose working depends on the principle of attraction or repulsion of electrodes that carry electrical charges such type of instrument is known as the electrostatic instrument.
- In other words, the instrument which uses the static electric field for producing the deflecting torque is known as the electrostatic instrument.
- The electrostatic instrument is used for measuring the high and low voltage and also the power of the given circuit.
Induction Type Instrument
- We use induction type instrument for AC measurement only. This is because the induction phenomenon only occurs in AC. An induction instrument has multi use. For example, we use the instruments as ammeters, voltmeters, wattmeters, and energy meters.
