Why sun always rises in the east ?

The sun 'rises' in the east because the sun spins on its axis in an easterly direction. The sun appears to rise in the east because the world turns constantly towards the east and while the sun sits still.

The Sun always rises in the east because the Earth rotates from west to east. Since we're riding on the Earth and also moving west to east with it, we see the Sun rise in the east.

Imagine flying toward the sun at about 12:00 in the afternoon and stopping about halfway between the sun and earth. Ok if turned around and looked back at the earth, here is what you would see. You would see that the sun is lighting up the whole side of the earth that is in your view. As time went by you would see that the earth is rotating from your left to your right. Up is north, down is south, on your left is west and on your right is east. So someone on the earth directly opposite from you is in the dark. But as the earth rotates, about 6 hours later, they’ll start to see you and the sun coming up in the east. Ok now fly to where that person is but stay the same distance from the earth. So you see the spot where the person is standing below you, but now the left side of the earth is in the dark and the sun is lighting up the right side. West is still on your left and east is still on your right. Ok so look to your right or east. What do you see? YES! You see the sun! Now go down to the earth where that person is but keep your eye on the sun as you go down. You see! When you’re standing on the earth you are looking east to see the sun and the sun is rising because you are moving toward the sun as the earth rotates!

If earth will revolve in opposite direction i.e. from east to west, then the sun will definitely rise from west

because we are looking for it in the east.

I think it is because of the rotaion of the earth..

it is because of the position of the earth