The circular motion of a particle with constant speed is

$A$ particle is acted upon by a force of constant magnitude such that its velocity and acceleration are always perpendicular to each other, then its

In uniform circular motion,the velocity vector and acceleration vector are

$A$ stone tied to the end of a string $1\,m$ long is whirled in a horizontal circle with a constant speed. If the stone makes $22$ revolutions in $44$ seconds,what is the magnitude and direction of the acceleration of the stone?

Assertion $(A)$ :- If a body is in a state of uniform circular motion,then its velocity and acceleration both are varying.
Reason $(R)$ :- If the magnitude of velocity is $v$ and the radius of uniform circular motion is $r$,then the magnitude of acceleration is $v^2/r$.

$A$ particle completes $2$ revolutions in a circular path of radius $3$ cm. The angular displacement of the particle will be (in radian) (in $\pi$)