Question

A convex lens of focal length 8 cm is to be used to form a virtual image 2 times the size of the object. Where must the object be placed from the
lens?​

Answer 1

Answer:

Your question is solved above

Answer 2

Answer:

To determine where the object must be placed from the lens in order to form a virtual image that is 2 times the size of the object, we can use the lens equation:

1/f = 1/u + 1/v

Explanation:

What are u and v ?

• f = focal length of the lens

• u = distance of the object from the lens

• v = distance of the image from the lens

For a virtual image, the image distance v is negative.

We are told that the image is 2 times the size of the object, so we can use the image size relationship:

image size / object size = -v/u

We know that the focal length of the lens is 8 cm and we are given that the image is 2 times the size of the object.

So we have:

-v/u = 2

Now we can substitute this into the lens equation:

1/8 = 1/u - 1/v

We know that the image is virtual so v is negative, so we can multiply both sides by -v to obtain:

-1/8 = -1/v - 1/u

If we multiply both sides by 8, we get:

1 = -1/u - 1/v

Now if we add 1 to both sides we get:

1 + 1 = -1/u - 1/v + 1

Which gives:

2 = -1/u

So we can find the distance of the object from the lens by multiplying both sides by -1, we get:

u = -1/2

Therefore, the object must be placed -1/2 cm from the lens in order to form a virtual image that is 2 times the size of the object.

Please note that this distance is negative because the object is on the same side of the lens as the virtual image formed.

To know more about virtual image , check out :

https://brainly.in/question/207559

To know more about object distance , check out :

https://brainly.in/question/3589366

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