Originally Posted by AlteredEgo
NO. You should not use a cable with a lower current capacity than the circuit breaker.
In general this is true. But since you've said that the dryer outlet that this is plugged into is a 30A breaker, you're fine using the 10AWG - although 100' is a long run, I'm not sure about that. You know how much 100' 10 gauge is going to cost you right?