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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
