Assertion: The resultant acceleration of an object in circular motion is towards the centre, if the speed is constant.
Reason: A vector is necessarily changed if it is rotated through an angle.
Important Questions on Circular Motion
Assertion: Work done by the centripetal force in moving a body along a circle is always zero.
Reason: In a circular motion, the displacement of the body is along with the force.
Reason : This is because they are always equal and opposite.
Assertion: Work done by centripetal force is zero.
Reason: Centripetal force acts perpendicular to the displacement.
Reason : Angular displacement is not an axial vector.
Reason : If a particle moves with variable velocity then acceleration must be present.
Assertion: In uniform circular motion speed of particles must be constant.
Reason: In uniform circular motion no force or acceleration is acting on particle acting parallel or in antiparallel to the direction of velocity.
Assertion: When the direction of motion of a particle moving in a circular path is reversed the direction of radial acceleration still remains the same (at the given point).
Reason: For a particle revolving on a circular path in any direction such as clockwise or anticlockwise, the direction of radial acceleration is always towards the centre of the circular path.
Assertion: For uniform circular motion it is necessary that the speed of the particle is constant.
Reason: There is no tangential force or tangential acceleration acting on particles in a uniform circular motion.
