Question 29

[h99h20baby]

I understand that the image is positive bc it is a real image. That makes since that -i/o = -M.

I do not understand how the second part plays out. If the object distance is 3x's bigger to the objective than the Fo the -i/o is less than one. Why is that? Does it have anything to do with the equation:

1/f = 1/o + 1/i??
Is it bc since the 1/f is smaller than 1/o the 1/i has to be smaller to balance the equation out? The image was positive? I am very confused.
Regards

[admin]

This is one of the rules of lenses (PHY 11.5): for a converging lens, the image formed depends on the object distance relative to the focal length f.

If o < f then the image is virtual and erect

If o > f then the image is real and inverted

If o = f then no image is formed.

These are the rules. If you want, you can confirm that i < o using the lens equation. Just replace o with 3f.

[h99h20baby]

Do you know it converging bc it is a convex lens? I thought convex was diverging? Or is that for mirrors?
regards

[admin]

Convex is converging for lenses, diverging for mirrors.

[farshar6436]

Thanks for the clarification. With regards to a diverging lens, would the image always be virtual, inverted or could you have a real image (ever) with a diverging lens?

Would the rule for convex lenses also apply to concave mirrors?

Thanks!

[alistar2005814]

how do you know the size of the image?

is it true that in convex lenses as you move away from the lens your image gets smaller and move closer your image gets enlarged.. is it true for all?

please explain how you can figure out the size without numbers!!!

[alistar2005814]

how do you know the size of the image?

is it true that in convex lenses as you move away from the lens your image gets smaller and move closer your image gets enlarged.. is it true for all?

please explain how you can figure out the size without numbers!!!

[mcat_premed3832]

You will find the calculation here: www.mcat-prep.com/forum/viewtopic.php?t=1569

Convex lens/image changes: www.phy.ntnu.edu.tw/ntnujava/index.php?topic=48

[admin]

Bump.

[hua8986059]

Good to be able to toss out 2x answers with erect right away because

Real image always inverted positive
Virtual image always upright Negative

RIP VUN

Thing that got me is not reading the question clearly where it said the image by the objective. I was doing this fast and thought that the eyepiece would magnify the image.....