Centrifugal force on a pendulum Why don't we consider the centrifugal force acting on the bob of a pendulum while drawing the Free Body Diagram of a pendulum? It's also a sort of circular motion.
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Why don't we consider the centrifugal force acting on the bob of a pendulum while drawing the Free Body Diagram of a pendulum? It's also a sort of circular motion.

First off, you meant centripetal rather than centrifugal. Circular motion requires a centripetal force, not a centrifugal force.

There are two forces acting on the pendulum bob: Gravitation, which is a constant force, and tension (or sometimes compression in the case of an inverted pendum) which is always directed toward or away from the central pivot about which the pendulum bob rotates. This tensile or compressive force is a constraint force. The magnitude and direction are always just that amount needed to keep the net radial component of force to be $m v^2/r$, directed toward the central pivot.
That tensile/compressive force does not need to be modeled -- unless one is asked "Will the pendulum rod (or string) break or buckle?" Assuming the rod/string does not break or buckle, the only motion of interest results from the tangential component of the net force. You don't need to model the radial component of the net force so long as the tensile/compressive force along/against the pendulum rod can satisfy the constraint.
