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The basic principle of moving iron instruments is it works on the principal of magnetic repulsion....
it consists of two irons one stationary n other fixed to a moving pointer
small current flows through a coil surrounding the irons.this creates a magnetic field ,which magnetise the two irons..
the magnetise iron will develop a repulsion force between each other, this will cause the pointer to move against the spring
the pointer stop moving when the spring tension equals the repulsion force between the magnets...
Wiki User
∙ 12y ago
Wiki User
∙ 13y agoa current carrying conductor placed in magnetic field. It experiences a force, it is given by
F=BIL
Where,
F=force in newton
B=flux density in tesla
I=current in amphere
L=length of conducter in meter.
Wiki User
∙ 12y agothese instruments operate on the interaction between two magnet field.the signal current to be measured routed through a fine wire coil suspended in the field of permanent magnet.the coil wound round an aluminium frame which is a cylendrical soft iron core.a spiral spring connected to the pointer returns it to zero when instrument is disconnected...
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Is Voltmeter is a moving iron Instrument or moving coil instrument?
If this is a homework related question, you really should consider trying to solve it yourself before looking at this answer. Otherwise, the value of the lesson, and the reinforcement provided by the assignment, will be lost to you.A moving coil measuring instrument has a coil attached to the indicator, surrounded by a magnet.A moving iron measuring instrument has a magnet attached to the indicator, surrounded by a coil.In both cases, the indicator is driven by magnetic torque caused by current flow in the coil.
Can moving coil galvanometer be used to detect ac in a circuit give reason?
Moving coil galvanometer is used to detect unknown resitance of the both ac or dc circuits :)deepak instrumentation engineerAnswerA 'galvanometer' is simply an instrument that detects and measures small currents; 'moving coil' describes its operating principle. A moving-coil galvanometer is a d.c. instrument; if subject to a.c., then it will simply vibrate as it will not be able to respond the the frequency (unless the frequency is very low, in which case, it will sweep back and forth in step with that frequency).The moving-coil principle is applied to other instruments, and can be used in the construction of multimeters. In the case of a multimeter, a rectifier circuit is incorporated so that it can be used to measure a.c. currents and voltages.
What happens when a permanent magnet moving coil instrument be connected in an ac current?
The torque on the moving coil will reverse at twice the frequency of the supply, causing the pointer to vibrate. High-quality a.c. measuring instruments that incorporate a moving coil are, of course, common but incorporate a rectification circuit to supply the coil.
Why moving iron is used in both AC and DC current?
A moving iron instrument works by means of a coil that attracts a moving iron mass that is attached to a pivoted pointer which moves across a graduated scale. The iron mass will be attracted towards the coil, regardless of the magnetic polarity of the coil. So, as an AC current continually reverses the magnetic polarity of the coil, the iron mass is always attracted towards the coil, never repelled by it. Similarly, a moving iron instrument doesn't care in which direction a DC current is flowing. So the instrument works equally well with both AC and DC currents. Moving iron instruments, however, are not as accurate as moving coil instruments which, of course, are sensitive to the direction of current.
What is the purpose of the series resistor in your designed ammeter circuit?
You appear to be referring to a 'swamping resistor' which is connected in series with a moving-coil ammeter's moving coil.To minimise any errors due to temperature changes in the resistance of the instrument's moving coil, the coil is connected in series with what is termed a 'swamping resistor' whose resistance is large in comparison with that of the moving coil, and which is manufactured from an alloy with a very lowtemperature coefficient of resistance (i.e. a metal whose resistance is hardly effected by wide variations in temperature).For example, if the resistance of a 1-Ω moving coil increases to, say, 1.1 Ω, when its rated current flows through it, this will introduce a 10% error in the instrument's reading.But by calibrating the instrument with a series swamp resistor of, say, 49 Ω, the overall resistance at rated current will become 50.1 Ω. This will result in an error of just 0.2%.A swamping resistor, then, is an integral part of all moving-coil instruments and, when we refer to an instrument's 'coil resistance', we actually mean the combined resistance of the moving coil itself and its swamping resistor.
What is the construction and working details of moving iron and moving coil ammeters and moving coil voltmeters?
Different b/w a moving coil instrument and a moving iron instrument
Is megger related to hot wire instrument moving coil or moving iron?
It is related to moving coil type instrument
What is moving coil voltmeter?
mic or moving iron coil is instrument type works on ac and dc
What is moving coil type voltmeters?
mic or moving iron coil is instrument type works on ac and dc
Is Voltmeter is a moving iron Instrument or moving coil instrument?
If this is a homework related question, you really should consider trying to solve it yourself before looking at this answer. Otherwise, the value of the lesson, and the reinforcement provided by the assignment, will be lost to you.A moving coil measuring instrument has a coil attached to the indicator, surrounded by a magnet.A moving iron measuring instrument has a magnet attached to the indicator, surrounded by a coil.In both cases, the indicator is driven by magnetic torque caused by current flow in the coil.
What are the disadvantages of moving coil instrument?
power must be gotten thru moving parts to the coil slip rings, festoons, tinsel
What are the functions of moving coil instrument?
The function of the moving coil is to deflect the instruments needle across a calibrated scale to give the meter operator an accurate reading of what ever he is testing. The moving coil is given a minute current, through internal instrument circuity, a sample of the potential that is being measured.
Can moving coil galvanometer be used to detect ac in a circuit give reason?
Moving coil galvanometer is used to detect unknown resitance of the both ac or dc circuits :)deepak instrumentation engineerAnswerA 'galvanometer' is simply an instrument that detects and measures small currents; 'moving coil' describes its operating principle. A moving-coil galvanometer is a d.c. instrument; if subject to a.c., then it will simply vibrate as it will not be able to respond the the frequency (unless the frequency is very low, in which case, it will sweep back and forth in step with that frequency).The moving-coil principle is applied to other instruments, and can be used in the construction of multimeters. In the case of a multimeter, a rectifier circuit is incorporated so that it can be used to measure a.c. currents and voltages.
What happens when a permanent magnet moving coil instrument be connected in an ac current?
The torque on the moving coil will reverse at twice the frequency of the supply, causing the pointer to vibrate. High-quality a.c. measuring instruments that incorporate a moving coil are, of course, common but incorporate a rectification circuit to supply the coil.
Why moving iron is used in both AC and DC current?
A moving iron instrument works by means of a coil that attracts a moving iron mass that is attached to a pivoted pointer which moves across a graduated scale. The iron mass will be attracted towards the coil, regardless of the magnetic polarity of the coil. So, as an AC current continually reverses the magnetic polarity of the coil, the iron mass is always attracted towards the coil, never repelled by it. Similarly, a moving iron instrument doesn't care in which direction a DC current is flowing. So the instrument works equally well with both AC and DC currents. Moving iron instruments, however, are not as accurate as moving coil instruments which, of course, are sensitive to the direction of current.
Why you called the watt-meter as dynamo-meter in the 3 phase power measurement?
The terms you are looking for are 'dynamometer' (no hyphen!) or 'electrodynamic' instrument. These terms describe an instrument movement, where the torque applied to the pointer results from the interaction of magnetic fields produced by fixed and moving coils. In the case of a wattmeter, the fixed coil is the current coil which is connected in series with the load, and the moving coil is the voltage coil which is connected in parallel with the load.A dynamometer type instrument differs from a moving-coil instrument, such as an ammeter or a voltmeter, in which the torque applied to the pointer is the result of the interaction between the magnetic fields produced by the moving coil and a permanent magnet.For three-phase power measurements, it is possible to use just two wattmeters in a configuration called the 'two wattmeter method'.
Working principle of permanent-magnet moving-coil instrument?
it will smash to each other & make flex
