Explain how a moving iron instrument attraction type operates?

Answer 1

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.

Answer 2

Moving Iron Vane Movement The moving iron vane movement can be used to measure both AC current and voltage. By changing the meter scale calibration, the movement can be used to measure DC current and voltage. The moving iron vane meter operates on the principle of magnetic repulsion between like poles. The measured current flows through a field coil which produces a magnetic field proportional to the magnitude of current. Suspended in this field are two iron vanes attached to a pointer. The two iron vanes consist of one fixed and one moveable vane. The magnetic field produced by the current flow magnetizes the two iron vanes with the same polarity regardless of the direction of current through the coil. Since like poles repel one another, the moving iron vane pulls away from the fixed vane and moves the meter pointer. This motion exerts a force against a spring. The distance the moving iron vane will travel against the spring depends on the strength of the magnetic field. The strength of the magnetic field depends on the magnitude of current flow. Figure 3 Moving Iron Vane Meter Movement As stated previously, this type of meter movement may also be used to measure voltage. When this type of movement is used to measure voltage, the field coil consists of many turns of fine wire used to generate a strong magnetic field with only a small current flow.

Answer 3

A plate or vane of soft iron or high permeability steel forms the moving element of system,this iron vane is so situated that it can move in a magnetic field produced by a stationary coil

Answer 4

attraction type and repulsion type