MP Board · Class 12 · Physics · Ray Optics and Optical InstrumentsThe focal length of a convex lens is $f$. When it is immersed in water (refractive index $4/3$), its focal length:
Step-by-Step Solution
When a glass lens is immersed in water, the relative refractive index decreases, which increases the focal length of the lens significantly.
Detailed Options Breakdown
Option : Decreases
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Ray Optics and Optical Instruments.
Option 1: Increases (Correct Answer)
Correct choice. Refer to the step-by-step verified solution guidelines above for details.
Option 2: Remains unchanged
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Ray Optics and Optical Instruments.
Option 3: Becomes zero
Incorrect choice. This distractor represents a common misunderstanding of the core principles of Ray Optics and Optical Instruments.
💡 Study Guide: This question tests core syllabus concepts from Ray Optics and Optical Instruments. For formulas, key summaries, and mock exam reference guides, read the full Ray Optics and Optical Instruments Revision Notes.