Why is the coil of a dead beat galvanometer wound on a metal frame?

what is a dead beat galvanometer?

Explain the construction, working and theory of dead beat galavanometer with the help of a suitable diagram.

Why is the core of moving coil galvanometer laminated?

It is desired to measure the magnitude of field between the poles of a powerful loud speaker magnet. A small flat search coil of area 2 cm^2 with 25 closely wound turns, is positioned normal to the field direction, and then quickly snatched out of the field region. Equivalently, one can give it a quick 90^@ turn to bring its plane parallel to the field direction). The total charge flown in the coil (measured by a ballistic galvanometer connected to coil) is 7.5 mC. The combined resistance of the coil and the galvanometer is 0.50 Omega . Estimate the field strength of magnet.

Why is the coil wrapped on a conducting frame?

Explain why the coils of the resistance box are wound over themselves?