Image Formation by Lenses

Q.

Why is a convex lens called a converging lens and a concave lens a diverging lens? [3 MARKS]

Q.

How do you tell if an image is upright or inverted?

Q. Which lens is used in peepholes of the door?
a)concave lens
b)convex lens

Q.

A concave lens always forms a virtual image.

1. True

2. False

Q.

Question 18

In a convex lens, an erect and enlarged image of an object is formed. Explain how this could be possible.

Q.

Question 8

An image formed by a lens is erect. Such an image could be formed by a

(a) convex lens provided the image is smaller than object.

(b) concave lens provided the image is smaller than object.

(c) concave lens provided the image is larger than object.

(d) concave lens provided the image is of the same size.

Q.

With concave mirrors we can obtain real, enlarged and inverted images.

1. False

2. True

Q.

Question 13

Observe the given figures carefully

The given figures show the path of light through lenses of two different types, represented by rectangular boxes A and B. What is the nature of lenses A and B?

Q.

Question 4

You are provided with a concave mirror, a convex mirror, a concave lens and a convex lens. To obtain an enlarged image of an object you can use either

(a) concave mirror or convex mirror.

(b) concave mirror or convex lens.

(c) concave mirror or concave lens.

(d) concave lens or convex lens.

Q. What is a virtual image?

1. The image that cannot be caught on a screen
2. The image that can be caught on a screen
3. The image that cannot be converged on a screen
4. None

Q.

The phenomenon due to which the right of the object appears to be the left of the image is known as:

1. dispersion

2. scattering of light

3. lateral Inversion

4. reflection of light

Q. What is lenses

Q.

Statement I : Virtual image cannot be projected on a screen.

Statement II : Divergent rays cannot form an image.

1. Statement II is incorrect, statement I is correct.

2. Statement I is the reason of the for statement II.

3. Both statements are incorrect.

4. Statement II is the reason for statement I.

Q. What are the images formed by the convex lens and concave lens ?

Q.

Why is convex mirror used as a rear-view mirror in vehicles?

1. Plane mirror, because it forms a virtual and erect image.

2. Concave mirror, because it forms real image.

3. Convex mirror, because it forms a virtual, erect and diminished image. And it also has more field of view than the plane mirror.

4. Lens is used instead of a mirror.

Q.

What is the nature of image formed in:
a. Concave lens
b. Convex lens
Also, give one use of each lens.[3 MARKS]

Q.

Which of these has virtual focus?

1. concave lens

2. convex lens

3. convex mirror

4. both (a) and (c)

Q. A convex(A) and concave(B) lens are aligned along a straight line as given below. If both their focal points meet each other at point F, which among the given statements are true?

1. Rays emerging from B will be diverging in nature.
2. Rays emerging from B will be converging in nature.
3. Incident rays on A will be parallel to emerging rays from B.
4. Rays entering B will be diverging in nature.

Q.

A concave lens is used in cameras to focus an image of the film. Is the statement true or false?

1. True
2. False

Q.

Question 2 (b)
Mark T if the statement is true and F if it is false:
A concave lens always forms a virtual image.

Q.

Among the given options, which is the most appropriate mirror that is small in size, but can form a full virtual image of a tall building?

1. A concave mirror

2. A plane mirror

3. A combination of a concave and a plane mirror

4. A convex mirror

Q.

Which of the following is/are necessary for the formation of an image?

1. Intensity

2. Object

3. Mirror

4. Light

Q. Which of the following is true about real images?

1. They are formed when reflected rays appear to meet at a point.
2. They are formed when reflected rays actually meet at a point.
3. They are formed when reflected rays diverge after reflection.
4. They cannot be obtained on the screen.

Q. Please send me a table form of image made by concave lens and mirror and convex lense and mirror of an object

Q. An object is placed at $90cm$ from the lens with the radius of curvature $40cm$. The central portion of a lens is wrapped in a black paper as shown below. How will the image change after wrapping the black paper?

1. The intensity of the image formed will increase.

2. The image formed will be diminished.
3. Image will not be formed.

4. The intensity of the image formed will decrease.

Q.

Which type of lens always forms a virtual image?

1. Concave lens

2. Convex lens

Q.

Question 9

The image formed by a lens is always virtual, erect and smaller in size for an object kept at different positions in front of it. Identify the nature of the lens.

Q. Where should the object be placed if we use convex lens to obtain real, inverted and diminished image?

1. Object should be placed at focal point
2. Object should be placed at infinity
3. Object should be placed at finite distance from Focal point
4. Object should be placed between F and 2F

Q.

Question 23

It was observed that when the distance between an object and a lens decreases, the size of the image increases. What is the nature of this lens? If you keep on decreasing the distance between the object and the lens, will you still able to obtain the image on the screen? Explain.

Q. Draw ray diagrams to show the formation of three times magnified (a) real, and (b) virtual image of an object by a converging lens. Mark the positions of O, F and 2F in each diagram.