PhysicsMedium105×since 2002Q7029Diameter of a plano-convex lens is 666 cmcmcm and thickness at the center is 3mm3mm3mm. If speed of light in material of lens is 2×108 m/s,2 \times {10^8}\,m/s,2×108m/s, the focal length of the lens isA151515 cmcmcmB202020 cmcmcmC303030 cmcmcmD101010 cmcmcmCheck answerSkip