Quick Answer: What are the differences between attraction and repulsion type instruments?

What is attraction and repulsion type moving instrument?

The attraction type instruments use spring, which provided the controlling torque. The deflection of the coil is reduced by the aluminium piston which is attached to the moving coil. 2. Repulsion Type Instruments – The repulsion type instrument has two vanes or iron plates. One is fixed, and the other one is movable.

What is the difference between MC and MI instruments?

The MI iron instrument has the non-uniform scale. … The moving iron instrument consumes more power as compared to the moving coil instrument. The moving iron instrument is used for measuring both the direct and alternating current whereas the moving coil is used for the DC measurement.

What is the difference between moving coil and moving iron instruments?

The moving iron instrument is used for measuring both the direct and alternating current whereas the moving coil is used for the DC measurement. … In moving iron instruments, the gravity or spring provides the controlling torque to the instrument.

What are the advantages and disadvantages of MI instrument?

The main advantage of Moving Iron Instrument is that it can measure AC as well as DC quantities. Though this instrument is responsive to DC, it suffers from hysteresis error which causes an appreciable error in the measurement of DC.

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What are MI and MC ammeters?

Comparison between moving-iron (M.I) instruments and moving-coil( M.C)instruments

M.I Instruments M.C Instruments
It can be used for a.c as well as d.c voltage and current measurement. It is suitable only for the d.c voltage and current measurement.

What is the difference between PMMC meter and dynamometer?

The difference between the PMMC and dynamometer type instrument is that the permanent magnet is replaced by an electromagnet. Principle of operation: When the current flows through the fixed coil, it produced a magnetic field, whose flux density is Proportional to the current through the fixed coil.

How are instrument transformers different from shunts and multipliers?

Explanation: Instrument transformers can be used for extending the range of the A.C. instruments. In instrument transformers, readings are independent of the values of R, L, and C. But in the case of shunts and multipliers, the readings depend on the values of circuit constants.

Which type of the instruments is used only for DC?

Permanent Magnet Moving Coil (PMMC) is only used for DC measurements. Moving Iron (MI) type instruments can be used for both AC & DC measurements.

What is PMMC full form?

A permanent magnet moving coil (PMMC) is one such instrument that is popularly used onboard and has several applications. The other popular nomenclature of this instrument is D’alvanometer and galvanometer.