English

A point object in the air is placed symmetrically at a distance of 60 cm in front of a concave spherical surface with a refractive index of 1.5. If the radius of curvature of the surface is 20 cm

Advertisements
Advertisements

Question

A point object in the air is placed symmetrically at a distance of 60 cm in front of a concave spherical surface with a refractive index of 1.5. If the radius of curvature of the surface is 20 cm, find the position of the image formed.

Numerical
Advertisements

Solution

We can use the mirror formula to find the position of the image formed by the concave spherical surface:

Since the object is placed symmetrically in front of the surface, we have:

u = 60 cm

Now, we can substitute these values into the formula:

`n_2/v - n_1/u = (n_2 - n_1)/R`

⇒ `1.5/v = (1.5 - 1)/(-20) + 1/(-60)`

⇒ `1.5/v = 0.5/(-20) - 1/60`

⇒ `1.5/v = -1/40 - 1/60`

⇒ `1.5/v = (-6 - 4)/240`

⇒ `1.5/v = (-10)/240`

⇒ `v = 240 xx 1.5/(-10) = -36`

Taking the reciprocal of both sides, we get:

`v = -36` cm

The negative sign indicates that the image is formed on the same side of the surface as the object, which means it is a virtual image. So, the image is formed 36 cm behind the concave spherical surface.

shaalaa.com
  Is there an error in this question or solution?
2022-2023 (March) Outside Delhi Set 2

RELATED QUESTIONS

A converging lens of focal length 15 cm and a converging mirror of focal length 10 cm are placed 50 cm apart with common principal axis. A point source is placed in between the lens and the mirror at a distance of 40 cm from the lens. Find the locations of the two images formed.


A point object is placed at a distance of 15 cm from a convex lens. The image is formed on the other side at a distance of 30 cm from the lens. When a concave lens is placed in contact with the convex lens, the image shifts away further by 30 cm. Calculate the focal lengths of the two lenses.


A ball is kept at a height h above the surface of a heavy transparent sphere made of a material of refractive index μ. The radius of the sphere is R. At t = 0, the ball is dropped to fall normally on the sphere. Find the speed of the image formed as a function of time for \[t < \sqrt{\frac{2h}{g}}\] . Consider only the image by a single refraction.


A spherical surface of radius R separates two medium of refractive indices µ1 and µ2, as shown in figure. Where should an object be placed in the medium 1 so that a real image is formed in medium 2 at the same distance?


A ray of light from a denser medium strikes a rarer medium at an angle of incidence i as shown in the figure. Refracted and reflected rays make an angle of 90° with each other. The angle of reflection and refraction are r and r'. The critical angle is ______.

 


Obtain an expression for refraction at a single convex spherical surface, i.e., the relation between μ1 (rarer medium), μ2 (denser medium), object distance u, image distance v and the radius of curvature R.


Assertion: If critical angle of glass-air pair `("μg" = 3/2)` is θ1 and that of water-air pair `("μw" = 4/3)` is θ2, then the critical angle for the water-glass pair will lie between θ1 and θ2.

Reason: A medium is optically denser if its refractive index is greater.


According to the Cartesian sign convention for refraction at a spherical surface, all distances are measured from:


Which effect is common for image shift in refraction at a plane surface?


When a light ray strikes a curved surface and refracts, the amount of bending depends on:


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×