big problem in object shadow

I have a big problem in object shadow.
If I create a large object and cast a shadow, it looks close, but it does not look far away.

Please help me.

You can change the shadow distance in the Quality Settings (Edit > Project Settings > Quality > Shadows > Shadow Distance). There are no shadows past that certain distance. I would suggest to use Baked Lighting on large Shadow Distances because Realtime lighting needs a lot of computing power.