Q18.For a concave lens of focal length f , the relation between object and image distance u and v, respectively, from its pole can best be represented by ( u = v is the reference line): (1) (2) (3) (4)
What This Question Tests
This question assesses the ability to interpret the u-v graph for a concave lens, understanding its image formation characteristics (always virtual, diminished, and between O and F) and applying lens formula with appropriate sign conventions.
Concepts Tested
Formulas Used
1/v - 1/u = 1/f
📚 NCERT Sections This Tests
9.15 — Apply Mirror Equation And The Condition:
Physics Class 12 · Chapter 9
9.15 Apply mirror equation and the condition: (a) f < 0 (concave mirror); u < 0 (object on left) (b) f > 0; u < 0 (c) f > 0 (convex mirror) and u < 0 (d) f < 0 (concave mirror); f < u < 0 to deduce the desired result.
9.19 — A Screen Is Placed 90Cm From An Object. The Image Of The Object On
Physics Class 12 · Chapter 9
9.19 A screen is placed 90cm from an object. The image of the object on the screen is formed by a convex lens at two different locations separated by 20cm. Determine the focal length of the lens.
9.8 — A Beam Of Light Converges At A Point P. Now A Lens Is Placed In The
Physics Class 12 · Chapter 9
9.8 A beam of light converges at a point P. Now a lens is placed in the path of the convergent beam 12cm from P. At what point does the beam converge if the lens is (a) a convex lens of focal length 20cm, and (b) a concave lens of focal length 16cm?
📋 Question Details
- Chapter
- Ray Optics
- Topic
- Lens formula and u-v graphs
- Year
- 2020
- Shift
- 05 Sep Shift 1
- Q Number
- Q18
- Type
- Graph based
- NCERT Ref
- Class 12 Physics Ch 9: Ray Optics and Optical Instruments
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