A dead-beat galvanometer shows a pointer that quickly comes to rest at a fixed reading because

eddy currents are set up in the metallic frame supporting the coil.
the magnet used in it has a very high strength.
the pointer attached to it has negligible mass.
the supporting frame is made of ebonite.

Correct answer: eddy currents are set up in the metallic frame supporting the coil.

Solution

A dead-beat galvanometer has its coil wound on a metallic (conducting) frame; the induced eddy currents oppose the motion, quickly damping oscillations so the pointer settles fast.

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