Q17.For an object placed at a distance 2. 4 m from a lens, a sharp focused image is observed on a screen placed at a distance 12 cm from the lens. A glass plate of refractive index 1. 5 and thickness 1 cm is introduced between lens and screen such that the glass plate plane faces parallel to the screen. By what distance should the object be shifted so that a sharp focused image is observed again on the screen? (1) 0. 8 m (2) 3. 2 m (3) 1. 2 m (4) 5. 6 m
What This Question Tests
This multi-step problem combines the lens formula with the concept of apparent shift caused by a glass slab, requiring calculation of focal length and then a new object position.
Concepts Tested
Formulas Used
1/f = 1/v - 1/u
Apparent shift = t(1 - 1/ฮผ)
๐ NCERT Sections This Tests
9.19 โ A Screen Is Placed 90Cm From An Object. The Image Of The Object On
Physics Class 12 ยท 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 โ A Beam Of Light Converges At A Point P. Now A Lens Is Placed In The
Physics Class 12 ยท 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?
9.16 โ The Pin Appears Raised By 5.0 Cm. It Can Be Seen With An Explicit Ray
Physics Class 12 ยท Chapter 9
9.16 The pin appears raised by 5.0 cm. It can be seen with an explicit ray diagram that the answer is independent of the location of the slab (for small angles of incidence).
๐ Question Details
- Chapter
- Ray Optics
- Topic
- Lens Formula and Spherical Aberration
- Year
- 2022
- Shift
- 25 Jul Shift 2
- Q Number
- Q17
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 9: Ray Optics
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