Motion in a Plane Test 6

For a body moving in uniform circular motion the speed attained  by the object will remain constant not the velocity as velocity depends on the direction of motion, and in circular motion the direction of the object changes at every point. As speed remains constant the acceleration will remain constant.

When an object moves along a circular path, it is called circular motion. During such a motion, the direction of motion at any point is given by the tangent at that point which changes continuously.

An accelerating body is an object that is changing its velocity. And since velocity is a vector that has both magnitude and direction, a change in either the magnitude or the direction constitutes a change in the velocity.
Hence a uniform circular motion is a accelerated motion because direction of motion keeps on changing

To describe the motion of a particle along a circle with a uniform speed. We need two variable, either x and y, or r and θ. Therefore, the motion of the particle is two-dimensional.

An object moving in uniform circular motion is moving in a circle with a uniform or constant speed. The velocity vector is constant in magnitude but changing in direction.
Hence, the motion of a racing car on a circular track changes it speed, that is, it increases or decreases speed during the drive not a case of uniform circular motion.