A convex mirror of radius of curvature 12 cm has its principal axis horizontal. A simple pendulum with a tiny bob is oscillating in front of the mirror such that centre of mass of the bob is 12 cm away from the mirror along the principal axis. Amplitude of oscillation is 3 cm and there is practically no damping. Length of the pendulum is sufficiently large and the plane of oscillation is such that the bob moves practically along the principal axis of the mirror. Path length of the image of the bob formed by the mirror is .....
(a) 4 cm
(b) 2 cm
(c) 0.7 cm
(d) 8 cm
