Q.Consider following statements regarding a simple microscope: (P) It allows us to keep the object within the least distance of distant vision. (Q) Image appears to be biggest if the object is at the focus. (R) It is simply a convex lens. (A) Only (P) is correct (B) Only (P) and (Q) are correct (C) Only (Q) and (R) are correct (D) Only (P) and (R) are correct

[!TLDR] A simple microscope does keep the object within D and is just a convex lens (P, R true), but the image is biggest when the object is near (not at) the focus, giving maximum -- not the stated -- magnific …

(P) is TRUE: the whole purpose of a simple microscope is to let the eye examine an object placed closer than D (within the lens's focal length), which the unaided eye could never focus on comfortably. (R) is TRUE: a simple microscope/reading glass/magnifying glass is, physically, nothing more than a single convex lens. (Q) is FALSE: with the object placed EXACTLY at the focus (u=f), the image forms at infinity, giving the MINIMUM magnifying power M_min=D/f, not the biggest; the biggest (maximum) magnifying power M_max=1+D/f instead occurs when the fin …

Check each statement against the simple-microscope derivation: object-within-D and convex-lens-only are both structurally true; then verify the M_min/M_max formulas to see th …

Assuming 'object at the focus' always maximises magnification, confusing it with the fact that image-at-infinity (u=f) actually gives the microscope' …