Thick lens will have shorter and consequently thin lens will have greater focal length. Because, For a thick lens, the optical path length of the light is more, than for a thin lens, thus, the bending of light will be more in case of a thicker lens. Consequently, it has a shorter focal length.
<h3><u>Answer</u></h3>
- Distance is equal to the Total Distance covered by a body, from the initial till the final point

- Displacement is equal to the shortest distance between two points.
- So we known that Distance can only be equal to or greater than the displacement and can never be shorter than the displacement.
- This is just common sense how can anything be shorter than the shortest path itself. But it can be equal to the shortest path
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<h3><u>Know </u><u>More</u></h3>
☯ Distance is a scalar quantity and has only magnitude but no direction.
☯ Displacement is a vector quantity and has both magnitude and direction.
☯ Distance can only have +ve values whereas displacement can be +ve, -ve or even be zero.