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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.
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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.
Explain how a moving iron instrument attraction type operates?
when our instrument is ready to use . We switch on the supply, and E.M.F will induced due to that E.M.F the starting torque will produce in the coil and it will deflect hte needle due to the E.M.F induced in the ckt .. it for A.C. purpose nw we can also use this for dc measurment by reversr this process .when we reverse this process the torque will reversed and the need will change its position due to deflecting torque . so by these we can use it on booth supplyes on A.C. as well as D.C...AnswerAn 'attraction type' moving-iron instrument consist of a coil, through which the test current is passed, and a pivoted soft-iron mass attached to the pointer. The resulting magnetic polarity at the end of the coil nearest the iron mass then induces the opposite magnetic polarity into the part of the iron mass nearest the coil, which is then drawn by attraction towards the coil, deflecting the pointer across a scale.
Specifically what are moving coil and moving iron used for measuring?
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.
What is iron loss?
Iron losses (Pi) are independent of of load which occur due to pulsation of flux in the core. Iron losses include both Hysteresis loss and eddy current loss and is same at all the loads.
How left-hand rule is used for finding direction of force of current carrying wire when electron is moving from east to west?
what is the direction of motion of current carrying wire when electron is moving from east to west
Why eddy current damping is not used in moving iron instruments?
because eddy current is produced by the heat produced in winding
What is MI in ammeter MI?
mi stands for moving iron in ammeter used only in alternating current circuits
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.
Why moving iron or hot wire type meters can be used for measuring both ac and dc quantities?
yes we can measure the ac and dc because current passes through certain resistance then heat generate. heat is square of current. so chang in direction of current does not effect on heat generated.
A 2 KW iron is used on a 100 V AC mains The current in the iron is?
The current in the iron will be 5 amperes.
Explain how a moving iron instrument attraction type operates?
when our instrument is ready to use . We switch on the supply, and E.M.F will induced due to that E.M.F the starting torque will produce in the coil and it will deflect hte needle due to the E.M.F induced in the ckt .. it for A.C. purpose nw we can also use this for dc measurment by reversr this process .when we reverse this process the torque will reversed and the need will change its position due to deflecting torque . so by these we can use it on booth supplyes on A.C. as well as D.C...AnswerAn 'attraction type' moving-iron instrument consist of a coil, through which the test current is passed, and a pivoted soft-iron mass attached to the pointer. The resulting magnetic polarity at the end of the coil nearest the iron mass then induces the opposite magnetic polarity into the part of the iron mass nearest the coil, which is then drawn by attraction towards the coil, deflecting the pointer across a scale.
What is a moving iron galvanometer?
A moving iron galvanometer is used to intensify the magnetic field by reducing the length of air gap across which the magnetic flux has to pass.
Why moving iron or hot wire types meters can be used for measuring both AC and DC quantites?
Hot Wire hot wire is a resistive device ir drop is the same regardless of frequency hot wire can measure power true power regardless of frequency or phase angle two wires for power current and voltage both to convert to a measured temperature integration speed depending on the mass of the wire(s) hot wire can be a bimetal spiral connected directly to the pointer on the scale Moving Iron: the moving iron has a spring connected to an iron bar in a coil dc or ac will cause the iron to be magnetized the amount of current will increase the deflection normal 50hz 60hz and dc differences are very small the iron will have induced eddy currents causing higher frequency to have less deflection 400hz on airplanes for lighter transformers... need a different calibration see "Wigginton voltage tester" simplest moving iron i know of one moving part, the iron well 2 if you count the little compass on top to tell dc polarity large solid core so different for 60Hz then dc by perhaps 10%
Specifically what are moving coil and moving iron used for measuring?
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.
What type of electricity is used for an electric iron?
Electricity having AC current.
Which of these must be used to create an electromagnet?
coils of wire, iron, and electric current
Which is true electric current running along a wire can be used to produce magnetic force or moving electrons through a magnetic field can produce an electric current?
They're both true, but I'm not comfortable with the way they're stated. I would have said: -- Electric current through a wire produces magnetic force. -- Moving electrons constitute an electric current, whether or not they're moing througha magnetic field.
