Q 9.21 Solution Ray Optics| CBSE Std 12 Physics

[@mehaa1101]

It is very helpful thank you so much 😢

[@hiddenbirds3506]

Sir in part a for concave lens we take u negative But we take positive for part b in the second case why?

[@sohammaiti8171]

Bro see where the rays are coming from, the Ray's direction is said to be +ve while the opposite direction is said to be -ve, the previous image had Ray's from right to right was -ve

[@Quickrangolis1976]

Very good explanation sir👍

[@_shubham-kushwaha_]

Sir but i think that equivalent focal length formula is not given in the ncert, so can we use it directly in exam

[@MakeMeScientific]

are you sure its not given, because if not we will have to use textbook method.

[@_shubham-kushwaha_]

Only 1/F=1/f1+1/f2 is given in ncert

[@MakeMeScientific]

ok i will revise soon.