- 1(current)
Q. No.A thin equi-convex lens of refractive index \(1.2\) is dipped in oil of index \(1.44.\) The lens has a power of \(2\) D (in air). When it is immersed in the oil, the focal length of the lens becomes:
| 1. | \(50\) cm | 2. | \(-50\) cm |
| 3. | \(-50/1.2\) cm | 4. | \(-50 \times1.2\) cm |
Subtopic: Â Lens Makers' Formula |
 57%
Level 3: 35%-60%
Hints
A double convex lens has a focal length of \(25\) cm. The radius of curvature of one of the surfaces is double of the other. What would be the radii if the refractive index of the material of the lens is \(1.5?\)
1. \(100\) cm, \(50\) cm
2. \(25\) cm, \(50\) cm
3. \(18.75\) cm, \(37.5\) cm
4. \(50\) cm, \(100\) cm
Subtopic: Â Lens Makers' Formula |
 78%
Level 2: 60%+
NEET - 2019
Hints
Links
A biconvex lens \((\mu=1.5)\) has a radius of curvature of magnitude \(20~\text{cm}\). Which one of the following options, best describes, the image formed by an object of height \(2\) cm placed \(30~\text{cm}\) from the lens?
| 1. | virtual, upright, height \(=0.5\) cm |
| 2. | real, inverted, height \(=4\) cm |
| 3. | real, inverted, height \(=1\) cm |
| 4. | virtual, upright, height \(=1\) cm |
Subtopic: Â Lenses |Â Lens Makers' Formula |Â Refraction at Curved Surface |
 71%
Level 2: 60%+
AIPMT - 2011
Hints
Links
- 1(current)
Q. No.
© 2026 GoodEd Technologies Pvt. Ltd.