how can find an electrical ac motor with outer diameter of approx. 100 mm and with minimum of 500 watt. power?

Answer 1

What is the purpose? where you are going to use ?Is it continuouse rating Intermittent ratings.If it intermittent rating go for a smal size drilling machine with double speed or use a suitable speed controller & use it for your pupose .These all high speed ,high torque ac motor it will not run continuously .It may be available in 120 volts /220 volta Ac even in 12v ,18,24v dc. If you need low torque use a table fan motor but wattage will be less.Best of luck.