Two covex lenses of same focal length are fixed in PVC pipe at a distance double to their focal length . What happens if a boy sees the moon with that arrangement
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Answered by
32
I think the image of moon will be at infinity. Because
as given convex lenses of same focal lenth are fixed in a PVC pipe at a distance of double to their focal length, then each convex lens is placed at the centre of curvature of other convex lens.
object lens will be facing parallel rays coming from moon.
we know that parallel rays when faces on convex lens converges on focal length.
Then image of moon will be forming at the middle of PVC pipe as it is focal point of both the convex lens.
This image on focal point will be acting as an object to eye lens.
It is clearly known that object when kept on focal point of a convex lens then the image forms at infinity.
Hence the boy will not be able to see the moon through PVC pipe with this arrangement.
as given convex lenses of same focal lenth are fixed in a PVC pipe at a distance of double to their focal length, then each convex lens is placed at the centre of curvature of other convex lens.
object lens will be facing parallel rays coming from moon.
we know that parallel rays when faces on convex lens converges on focal length.
Then image of moon will be forming at the middle of PVC pipe as it is focal point of both the convex lens.
This image on focal point will be acting as an object to eye lens.
It is clearly known that object when kept on focal point of a convex lens then the image forms at infinity.
Hence the boy will not be able to see the moon through PVC pipe with this arrangement.
prajapatyk:
how?
for image formation there should be convergence of rays and any how the convergence through the first lens acts as an object to second lens so the rays from the focal point of first lens does not converge image forms at infinity .... i think
to form an enlarged image there should three convex lens of different sizes according to my reference of eamcet book
so what is the final answer
sorry if i am wrong please inform me the correct ans
do you think image forms at infinity that means the boy will not be able to see the moon?
yes
this is what I wrote.you just read my answer once again
yes i read just supporting your ans
ok thankyou
Answered by
39
Here two convex lens of same focal length are fixed in a PVC pipe at a distance double to their focal length.Then following process will happen:
1.A parallel beam of light rays will converge on focal point of the lens after refraction.
2. So image of moon appear as a point size on focus.
3. This point size images formed at focus will act as object for second lens.
4. Then light rays through focal point will be parallel to principal axis after refraction.
5. so when a boys sees through other end of PVC pipe he gets enlarged image of moon as rays are parallel after reflection.
Hence boy can see enlarged image of moon through other end of PVC pipe.
1.A parallel beam of light rays will converge on focal point of the lens after refraction.
2. So image of moon appear as a point size on focus.
3. This point size images formed at focus will act as object for second lens.
4. Then light rays through focal point will be parallel to principal axis after refraction.
5. so when a boys sees through other end of PVC pipe he gets enlarged image of moon as rays are parallel after reflection.
Hence boy can see enlarged image of moon through other end of PVC pipe.
Attachments:
mam sorry to disturb you is the answer which you have given is correct just to conform
Yes.
r u from telangana
it's correct
yes mam thank u
Is it correct mam
check the diagram and read question you will understand
sorry for disturbing mam but object kept on focal point of any convex lens do not form any image
Then how here the image appears large
i think the convergence of rays happens in eyes that is retina
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