Abstract: The regression equation of angular velocity of a nonmagnetic revolving metal plate is deduced by using the Faraday’s law of induction. Then，both frictional damping coefficient and electromagnetic damping coefficient are defined and measured. Lastly，the relationship between the electromagnetic damping coefficient and the value of exciting current is analyzed.

Key words: revolving metal plate, frictional damping coefficient, electromagnetic damping coefficient, regression equation of angular velocity