Refraction at Curved Surfaces

Q.

Difference between rarer and dense medium

Q. For refraction at a curved surface, the u-v relationship is: $\frac{{\mu }_2}{v}-\frac{{\mu }_1}{u}=\frac{{\mu }_2-{\mu }_1}{R}$

1. ${\mu }_2$ is the refractive index of the medium, at which the refraction takes place.
2. ${\mu }_1$ is the refractive index of the medium, from where the light is incident on the surface.
3. R is the radius of curvature of the refractive surface.
4. R can be positive or negative.

Q. What happens to the image, if a convex lens is made up of two different transparent materials as shown in figure?

Q.

If an object is placed in front of a convex mirror, the image will be

1. real

2. virtual

3. inverted

4. enlarged

Q. What is the difference between optical density and mass density

Q. The lateral shift in rectangular glass slab depends on

1. Thickness of glass slab
2. Angle of incidence
3. Refractive index
4. All of the above

Q. Suppose you are inside the water in a swimming pool. Your friend is standing on the edge. Do you find your friend taller or shorter than his actual height? Why? [3 Marks]

Q. An equiconvex lens of refractive index (3/2) and focal length 10cm is held with its axis vertical and its lower surface immersed in water (4/3).the upper surface being in air. At what distance from the lens will a vertical beam of parallel light incident on the lens be focused?

Q.

A far point person suffering from myopia is 2m from the eye. Find the the focal length and power of corrective lens that will correct his vision.

Q.

A lens which has two spherical surfaces both curved inside is called ___

1. concave lens

2. convex lens

3. plano-convex lens

4. plano-concave lens

Q.

A person suffering from myopia can see upto 3m.The power of lens required to rectify is

1. -4.00 D

2. -3.33 D

3. -0.33 D

4. -1.75 D

Q.

When light travels from a rarer to a denser medium, it bends -

Q.

What are thin lenses?

1. Apparture = Radius of curvature

2. Apparture > Radius of curvature

3. Apparture < Radius of curvature

4. None of these

Q. What will be the behaviour of a lens, if it is placed in water instead of air?

Q.

If light source is at focus of concave lens, then after refraction the ray of light will __.

1. parallel to principal axis

2. will appear to be parallel to principal axis

3. cannot be said

4. will never be parallel to principal axis

Q. On what factors does the focal length of a lens depend?
[2 MARKS]

Q.

The ray diagram shows the image of an object formed by a converging lens. What is the focal length of the lens?

Q. What is the near point of a person suffering from hypermetropia?

Q.

When and how does a convex lens behave like a concave lens?

Q. Locate the image of the point object O in the situation shown in the figure. The point C denotes the centre of curvature of the separating surface.

1. 30 cm, left
2. 30 cm, right
3. 20 cm, right
4. 20 cm, right

Q. In presbyopia, the near point of the eye gradually recedes away. Thus it is a case similar to hypermetropia. The why shouldn't we use a convex lens to correct this defect instead of a bifocal lens?

Q.

3.(C) How does the velocity of light vary with change in the optical density of the media?

Q.

A person suffering from myopia cannot see clearly beyond 1 m. What should be the focal length of the concave lens that will correct his vision?

1. 1 m

2. 2 m

3. 4 m

4. 0.5 m

Q. For refraction at a curved surface identify the wrong statement with accordnce to the curved surface formula.

1. ${\mu }_2$ is the refractive index of the medium, at which the refraction takes place.
2. ${\mu }_1$ is the refractive index of the medium, from where the light is incident on the surface.
3. R is the radius of curvature of the refractive surface.
4. R is always positive.

Q. Match the following lenses with their names.

1. Bi-convex
2. Bi-concave
3. plano-convex

Q. I saw a question that a person is suffering from myopia and he has a far point of 80cm. In its solution it is mentioned that the object distance is infinity. How come it be?

Q.

Question 17
A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?

Q.

Why do we close our eyes when flashed with strong light?

Q. What among the following is true about refraction?

1. Velocity of light in rarer optical medium is greater compared to the denser medium.
2. Velocity of light in rarer optical medium is lesser compared to the denser medium.
3. Refraction does not happen in more than two media.
4. Refraction can happen only when light travels from an optically rarer medium to a denser medium.

Q.

Which lens is converging: (i) an equiconcave lens or an equiconvex lens? (ii) a concavo-convex lens or a convexo-concave lens?