If we have Galois covering $$X\longrightarrow P^{1}_{\mathbb{Q}}$$ defined over rationals which is cyclic. I mean the Galois Group associated to the covering is cyclic group. 
Then X can not be $P^{1}_\mathbb{Q}$

I read it somewhere, Is this result true.

I tried this over complex number and I found that over complex number it is true,

$P^{1}_{\mathbb{C}} \longrightarrow P^{1}_{\mathbb{C}}$ defined by $z$ going to $z^{n}$.