A three-phase, $4$-pole, self excited induction generator is feeding power to a load at a frequency $f_1$. If the load is partially removed, the frequency becomes $f_2$. If the speed of the generator is maintained at $1500$ $rpm$ in both the cases, then
- $f_1,f_2> 50Hz$ and $f_1> f_2$
- $f_1< 50 Hz$ and $f_2> 50 Hz$
- $f_1,f_2< 50Hz$ and $f_2> f_1$
- $f_1>50 Hz$ and $f_2< 50 Hz$