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Specifically what are moving coil and moving iron used for measuring?
Wiki User
∙ 7y ago
If you are questioning about different relay (contactor) constructions, the terms moving coil and moving iron designate what part of the relay moves and carries the conductor that makes or breaks a circuit.
Wiki User
∙ 14y ago
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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.
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 a DC voltmeter and DC ammeter cannot read AC?
Obviously, it's a voltmeter that measures a.c. voltages. The most common types are a 'moving iron' type or a 'moving coil' type. The latter requires a rectifier circuit. Both scales are calibrated to indicate root-mean-square values. Moving-iron scales are non-linear, whereas moving-coil scales are linear. Moving-iron types are less accurate than moving-coil types.
Why are moving iron test instruments not used with DC although they can work in DC?
For moving-iron instrument magnetic field is caused when the current (voltage) passes the fixed circle. When the current (voltage) passes the fixed circle，the two iron plates are magnetized ,rotational torque is resulted, the deflection angle indicate measured current. Because the magnetized polarity is same for AC or DC, moving-iron instrument can be used in AC and DC circuit. For permanent-magnet moving-coil instrument magnetic field is caused by the permanent-magnet, When the DC current passes the moving coil, rotational torque is resulted,so the deflection angle indicate measured DC current. As AC current passes the moving coil ,because inertia of moving parts of meter the deflection angle indicate rotational torque average, but rotational torque average is zero in cycle, moving parts of meter is´t deflec,so permanent-magnet moving-coil instrument only is used in DC circuit.
State principle of moving coil galvanometer?
Principle of Working:A Moving Coil Galvanometer works on the Electromagnetic effect of current carrying coil (free to move) being placed in an air-gap between the soft iron core and the strong pole pieces of the magnet.The current following in the moving coil which is the specimen to be sensed or measured results in a generation of a Magnetic Field which is opposite to that of the fixed magnetic pole pieces. And as like poles attract each other results in a generation of small deflecting torque which further deflects the pointer or the mirror attached to the axis of the coil.Construction:Moving Coil:The Moving coil which is free to move is being suspended from a soft metallic (non-magnetic) strip carrying the current specimen which is to be sensed or measured. The Moving coil is being suspended in the air-gap available between the fixed Soft Iron-Core and the fixed pole pieces of the magnet.The Soft Iron Core is used to provide a path of low reluctance so as to focus the magnetic field generated by the fixed magnetic pole pieces towards the moving coil. The use of low reluctance Soft Iron-Core helps to increase the sensitivity of the Galvanometer as well.In many of the Moving Coil Galvanometer Construction Soft Iron-Core pieces are removed and this results in the reduction of the sensitivity of the Galvanometer as a whole. In absence of the soft fixed iron core in the middle of the coil the coil then is narrowed in order to reduce the free air space, this narrowing of the coil results in the reduction of the Moment of Inertia(MI) of the moving coil arrangement. This results in having a good near to critical damping with very less oscillations.The Moving coil consists of a large number of turns wounded on a former which can either be in rectangular or circular in shape. The current carrying coil is made up of a thin non magnetic metal so as to have low resistance and less mass.Damping:Damping in Moving Coil Galvanometer is provided by an Eddy current damping mechanism. The damping is made as such to have a nearly critical damping by setting the device to be between under-damped and critical damped case.Controlling Torque:Spring Control mechanism is largely utilized to provide the suitable controlling torque.
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 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.
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
What does mc and mi refer to in voltmeter and ammeter?
moving coil & moving iron
Differences between Permanent magnet moving coil and moving iron?
Answer submit troll
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 will happen in the absence of iron cylinder in a moving coil galvanometer?
it will not work
How does a moving iron loudspeaker work?
Typical scheme of measuring el. current and voltageThe deflecting torque in any moving-iron instrument is due to forces on a small piece of magnetically 'soft' iron that is magnetized by a coil carrying the operating current. In repulsion type moving-iron instrument consists of two cylindrical soft iron vanes mounted within a fixed current-carrying coil. One iron vane is held fixed to the coil frame and other is free to rotate, carrying with it the pointer shaft. Two irons lie in the magnetic field produced by the coil that consists of only few turns if the instrument is an ammeter or of many turns if the instrument is a voltmeter.Current in the coil induces both vanes to become magnetized and repulsion between the similarly magnetized vanes produces a proportional rotation. The deflecting torque is proportional to the square of the current in the coil, making the instrument reading is a true 'RMS' quantity Rotation is opposed by a hairspring that produces the restoring torque. Only the fixed coil carries load current, and it is constructed so as to withstand high transient
What is the role of the soft iron core?
In a moving coil galvanometer, soft iron core intensifies the magnetic field through it. this causes maximum number of magnetic field lines to pass through the coil.
What are the kinds of ammeter?
The ammeter is a device that measures the electric current. Hot wire, electrostatic, moving iron, moving coil, and induction are the kinds of ammeter.
