f = PN/120 where f is frequency of power supply, P is number of poles in the machine and N = speed in rpm. So, Synchronous speed N = 120f/P. Thus for 50 Hz supply, 2 pole machine; synchronous speed = 3000rpm. ETRICAL
Within our solar system quite a bit of exploration has been done by spacecraft including orbiters and landers. Planets outside our solar system will be difficult or impossible to explore with spacecraft in our lifetimes, so astronomers and astrobiologists use other techniques to search for signs of life on these planets. In particular, astronomers are interested in planets within the habitable zone of stars.
As the planets in our Solar System get further away from the Sun, they generally get colder. So what is the coldest planet of our Solar System. That would be Neptune, the 8th and final planet in the Solar System. If Pluto was still a planet, it would be colder, but now itâs Neptune. Clouds of Neptune. Neptune is located 4.5 billion km from the Sun, on average, and it receives a fraction of the sunlight that the other planets receive.