(iii) A convex lens has 20 cm focal length in air. What is focal length in water ? (Refractive index of air-water = 1.33. Refractive index for ar - gl

Question

(iii) A convex lens has 20 cm focal length in air. What is focal length in water ? (Refractive index of air-water = 1.33. Refractive index for ar - gl

(iii) A convex lens has 20 cm focal length in air. What is focal length in water ?
(Refractive index of air-water = 1.33. Refractive index for ar - glass = 1.5.)

Monjur Alahi

5 views

2025-01-04 04:42

1 Answers

Related Questions

A lens has a power of 10 D, when placed in air. When it is immersed in water `(mu =(4)/(3))` the change in power is (refractive index of lens material

2 Answers 7 Views

A convex lens of refractive index 3/2 has a power of `2.5^(@)`. If it is placed in a liqud of refractive index 2,the new power of the lens is

2 Answers 6 Views

We combined a convex lens of focal length `f_(1)` and concave lens of focal lengths `f_(2)` and their combined focal length was F . The combination of

2 Answers 6 Views

When an object is placed 40cm from a diverging lens, its virtual image is formed 20cm from the lens. The focal length and power of lens are

2 Answers 4 Views

(i) If f = 0.5 m for a glass lens, what is the power of the lens ? (Refractive index of air-water = 1.33. Refractive index for ar - glass = 1.5.)

2 Answers 4 Views

(ii) The radii of curvature of the faces of a double convex lens are 10 cm and 15cm. Its focal length is 12 cm. What is the refractive index of glass

2 Answers 4 Views

What is the focal length of a convex lens of focal length 30 cm in contact with a concave lens of focal length 20 cm ? Is the system a converging or a

2 Answers 8 Views

c) Magnifying power of a simple microscope is inversely proportional to the focal length of the lens. What then stops us from using a convex lens of s

2 Answers 4 Views

A convex lens is made out of a substance of 1.2 refractive index. The two surface of lens are convex. If this lens is placed in water whose refractive

2 Answers 4 Views

Find the velocity of light in water, if its velocity in glass of refractive index 1.5 is `2 xx 10^(8)m//s`. The refractive index of water is 1.33.

2 Answers 4 Views

Salim Ahmed Kawsar · Accepted Answer · 2023-02-05T15:29:48+06:00

Salim Ahmed Kawsar

iii) For a glass lens in air, `n_(2)=1.5, n_(1)=1. f=+20cm`. Hence, the lens formula gives.
`(1)/(20)=0.5[(1)/(R_(1))-(1)/(R_(2))]`
For the same glass lens in water.
`n_(2)=1.5, n_(1)=1.33`. Therefore,
`(1.33)/(f)=(1.5-1.33)[(1)/(R_(1))-(1)/(R_(2))]`
Combining the above two equations, we find `f=+78.2cm.`

5 views Answered 2023-02-05 15:29