Image Formation by Concave Lens

Q. The characteristic(s) of the image formed by a concave lens when an object is placed at infinity is/are:

1. Virtual and Erect
2. Real and Inverted
3. Highly diminished
4. Formed at focus

Q. An object is placed $6\text{cm}$ in front of a concave mirror. A real image of the same size as the object is obtained. Find out the focal length of the mirror.

1. $6\text{cm}$
2. $12\text{cm}$
3. $1.5\text{cm}$
4. $3\text{cm}$

Q. An object is placed at a distance of $30cm$ from the lens. Its image is formed at a distance of $10cm$ on the same side of the lens. Find the focal length of the lens used.

1. $f=-10cm$
2. $f=+15cm$
3. $f=-15cm$
4. $f=10cm$

Q. What type of image is formed by concave lens ?

Q. An object is placed at a distance of $30cm$ from the lens. Its image is formed at a distance of $10cm$ on the same side of the lens. Find the focal length of the lens used.

1. $f=-15cm$
2. $f=10cm$
3. $f=+15cm$
4. $f=-10cm$

Q. Find out the distance of the image formed by the concave mirror from the pole, if the first image formed by the plane mirror is taken as an object for the given concave mirror.

1. $20\text{cm}$
2. $60\text{cm}$
3. $40\text{cm}$
4. $30\text{cm}$

Q.

A Convex lens is covered vertically half with black paper. An object is kept in front of the mirror. Can the image of the object be formed? If an image is formed, then what is the nature of the image

Q. The nature of image formed when an object is placed near to a concave lens is _____

1. Virtual diminished
2. Virtual magnified
3. Real magnified
4. Real diminished

Q. The final image formed by an astronomical telescope is:

1. virtual and erect.
2. real and inverted.
3. real and erect.
4. virtual and inverted.

Q. When an object approaches a convex lens from infinity, the image formed by it shifts

1. away from the lens
2. first away and then toward the lens
3. towards the lens
4. first towards and then away from the lens

Q. A point object is held above a thin equiconvex lens at its focus. The focal length is $0.1m$ and the lens rests on a horizontal thin plane mirror. The final image will be formed at :

1. $0.1m$ above the center of the lens
2. Infinite distance above the lens
3. Infinite distance below the lens
4. $0.1m$ below the center of the lens