Verified Solution • 2025–26 Session moderate

QNEET-2023-Ph-233: NEET 2023 Physics - Class 12 NEET-2023-Ph-233 Solution: In the figure shown here what is the equivalent focal length of …

In the figure shown here what is the equivalent focal length of the combination of lenses (Assume that all layers are thin)? -40 cm -100 cm -50 cm 40 cm

Multiple Choice Options

A $-40 \mathrm{~cm}$ _ 40 cm
B $-100 \mathrm{~cm}$ _ 100 cm
C $-50 \mathrm{~cm}$ _ 50 cm
D $40 \mathrm{~cm}$ 40 cm

Step-by-Step Verified Solution

Use 1 f = [ _ _ 1 ] [ 1 R 1 _ 1 R 2 ] 1 f 1 = [ 1.6 _ 1 ] [ 1 � _ 1 20 ] = _ 3 100 1 f 2 = [ 1.5 _ 1 ] [ 1 20 + 1 20 ] = 1 20 1 f 3 = _ 3 100 1 f e q = 1 f 1 + 1 f 2 + 1 f 3 1 f e q = _ 3 100 + 1 20 _ 3 100 = _ 1 100

Related Learning Resources & Exam Preparation

NEET PYQ Question Bank

Browse year-wise authentic previous years' questions with solutions

Authentic CBT Mock Tests

Simulate official exam environment with live timer and percentile scoring