JEE Main & Advanced
Physics
Ray Optics
Question Bank
Refraction at Curved Surface
question_answer
A symmetric double convex lens is cut in two equal parts by a plane perpendicular to the principal axis. If the power of the original lens was 4 D, the power of a cut lens will be [MP PMT 1999]
A) 2 D
B) 3 D
C) 4 D
D) 5 D
Correct Answer:
A
Solution :
\[P={{P}_{1}}+{{P}_{2}},\] if \[{{P}_{1}}={{P}_{2}}={P}'\] Þ \[{P}'=P/2=2D.\]