Three students measured the focal length of a convex lens using parallel rays from a distant object- All of them measured the distance between the lens and the inverted image on the screen-i Student A saw a sharp image on the screen and labelled the distance as f1ii Student B saw a slightly larger blurred image on the screen and labelled the distance as f2iii Student C saw slightly smaller blurred image on the screen and labelled the distance as f3The relation between the three measurements would most likely be1 f1-f2-f32 f1-f2-f33 f3-f1-f24 f1-f2 and f1-f3

673

You visited us 673 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard X

Physics

Linear Magnification

Three student...

Question

Three students measured the focal length of a convex lens using parallel rays from a distant object. All of them measured the distance between the lens and the inverted image on the screen.
(i) Student A saw a sharp image on the screen and labelled the distance as f₁
(ii) Student B saw a slightly larger blurred image on the screen and labelled the distance as f₂
(iii) Student C saw slightly smaller blurred image on the screen and labelled the distance as f₃

The relation between the three measurements would most likely be
(1) f₁ = f₂ = f₃
(2) f₁ < f₂ < f₃
(3) f₃ < f₁ < f₂
(4) f₁ < f₂ and f₁ = f₃

Open in App

Solution

A convex mirror converges all the rays coming from the distant object on its focus. According to given conditions, we can say if a sharp image is obtained at f₁, then f₁ must be the focal point of the lens. Now if the distance between the screen and the lens is varied then beyond the focus f₁, the image obtained would be large and blurred and behind the focus f_1,the image would be smaller and blurred.

Hence, the correct answer is option 3.

Suggest Corrections

Similar questions

Q. A sharp image of a distant object is obtained on a screen using a convex lens. In order
to determine the focal length of a lens, a student needs to measure the distance between:

Q. While performing an experiment on determining the focal length of a convex lens, a student obtains a sharp inverted image of the laboratory window grill on the screen and measures the distance between the screen and the lens. She then repeats the experiment and takes a distant tree as the object in the second case. In order to get a sharp image of the tree on the screen, she will now have to move the screen:
(1) slightly nearer to the lens
(2) slightly farther away from the lens
(3) very close to the lens
(4) very far away from the lens

Q. Student obtains a blurred image of a distant object on a screen using a convex lens. To obtain a distinct image on the screen he should move the lens.

A student obtained a blurred image of an illuminated distant tower on a screen by using a convex lens In order to obtain sharp image of the tower on the screen, he must shift the lens:

A student has obtained an image of a distant on a screen to determine the focal length $F_{1}$ of the given lens. His teacher, after checking the image, gave him another lens of focal length $F_{2}$ and asked him to focus the same object on the same screen. The student found that to obtain a sharp image, he has to move the lens away from the screen. From this finding, we may conclude that both the lenses given to the student were:

Join BYJU'S Learning Program