Question:
PMMC type instrument normally used for:
PMMC type instrument normally used for:
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Always remember — PMMC instruments rely on magnetic interaction, so eddy current damping (not air or fluid) is most natural.
Updated On: Jun 24, 2025
- air friction damping
- fluid friction damping
- eddy current damping
- under damped system
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The Correct Option is C
Solution and Explanation
PMMC (Permanent Magnet Moving Coil) instruments are widely used in analog measuring devices like voltmeters and ammeters.
They operate on the principle that a current-carrying coil placed in a magnetic field experiences a torque.
For damping, PMMC instruments use a non-magnetic but conductive material (like aluminum) attached to the moving coil.
As the coil moves, eddy currents are induced in this material due to the motion in the magnetic field.
These eddy currents create an opposing magnetic field that provides damping.
Hence, eddy current damping is the standard damping mechanism in PMMC instruments.
They operate on the principle that a current-carrying coil placed in a magnetic field experiences a torque.
For damping, PMMC instruments use a non-magnetic but conductive material (like aluminum) attached to the moving coil.
As the coil moves, eddy currents are induced in this material due to the motion in the magnetic field.
These eddy currents create an opposing magnetic field that provides damping.
Hence, eddy current damping is the standard damping mechanism in PMMC instruments.
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