Refraction by Spherical Lenses

An object of height $3 \mathrm{cm}$ is placed at $10 \mathrm{cm}$ from a concave lens of focal length $15 \mathrm{cm}$. Select the correct size of the image.

An object is placed at a distance $20 \mathrm{cm}$ from a convex lens of focal length $10 \mathrm{cm}$. Select the correct image distance and nature of the image.

The convex lens always gives small virtual image.

The power of lens depends on the focal length of the lens.

Assertion: Virtual images are always erect.

Reason: Virtual images are formed by diverging lenses only.

Name the lens whose thickness cannot be deemed negligible.

The lens whose thickness is not negligible is known as thin lens.

What do you mean by thick lens?

The lens is always formed from a sphere. What is the name of the centre of the sphere called?

What is the centre of the sphere from which the lens is formed called?

The centre of curvature is the centre of the sphere from which the lens is made.

What is centre of curvature of a lens?

A small object is placed in front of convex lens of focal length $25 \mathrm{cm}$ , such that a virtual image is formed at a distance of $25 \mathrm{cm}$. The magnification produced is 

A _____ (convex / concave) lens can produce both real and virtual images.

Which lens diverges the light rays falling on it?

Which lens is used as a magnifying glass - convex lens or concave lens?

An object is placed at a distance of $60 \mathrm{cm}$from the convex lens of focal length $30 \mathrm{cm}$. If object height is $3 \mathrm{cm}$ then find the position and nature of the image.

At what distance from a convex lens of focal length $24 \mathrm{cm}$, should an object be placed so that the lens forms an image of the same size as the object?

To obtain a magnification of, $-\frac{1}{2}$ with a convex lens, the object should be placed:

You are given two convex lenses $I$ and $II$ made of the same glass. $I$ is thicker than $II$ . Choose the correct answer from the following.