Question

A double convex lens of focal length 6 cm is made of glass of refractive index 1.5. The radius of curvature of one surface is double that of the other surface. The value of smaller radius of curvature is:

Solution

Correct option is

4.5 cm

 

    

Solving, we get R = 4.5 cm.

SIMILAR QUESTIONS

Q1

Time taken by sunlight to pass through a window of thickness 4 mm whose refractive index is 1.5 is: 

Q2

A ray of light is incident on the surface of separation of a medium with the velocity of light at an angle 45o and is refracted in the medium at an angle 30o. What will be the velocity of light in the medium

Q3

A ray of light falls on a transparent glass slab with refractive index (relative to air) of 1.62. The angle of incidence for which the reflected and refracted rays are mutually perpendicular is: 

Q4

A concave mirror of focal length f produces an image n times the size of the object. If the image is real, then the distance of the object from the mirror is:    

Q5

A convex mirror of focal length f produces an image (1/n)th of the size of the object. The distance of the object from the mirror is: 

Q6

A short linear object of length L lies on the axis of a spherical mirror of focal length f at a distance u from the mirror. Its image has an axial lengthL’ equal to: 

Q7

A thin convergent glass lens (μg = 1.5) has a power of +5.0 D. When this lens is immersed in a liquid of refractive index  it acts as a divergent lens of focal length 100 cm. The value of μl must be:

Q8

The sun (diameter = D) subtends an angle of θ radians at the pole of a concave mirror of focal length f. The diameter of the image of the sun formed by the mirror is: 

Q9

Diameter of a plano-convex lens is 6 cm and thickness at the centre is 3 mm. If the speed of light in the material of the lens is , the focal length of the lens is:  

Q10

A luminous point is moving at speed v0 towards a spherical mirror, along its axis. Then the speed at which the image of this point object is moving is given by (with R = radius of curvature and u = object distance):