Does a Silvered Plano-Convex Lens Act Like a Concave Mirror?

[sarthak sharma]

If the plane surface of a plano-convex lens in silvered then which of the following statements is true?

1. it acts like a convex mirror
2. it acts like a concave mirror
3. it acts like a concave lens
4. no changemy attempt---

the incident ray on the convex surface of the plano-convex will first converge (refract) then reflect from silvered plane surface towards the first surface and then from there it will diverge (refract again) towards the incident side only.

so i came to a conclusion that the combination is diverging on the same side as object and thus it acts like a Convex Mirror

but my book give the answer as a concave mirror and the same answer i get after browsing the net but could not find a proper explanation for itcan someone please help me out asap as my exams are pretty much close now...

 

[sarthak sharma]

@collinsmark @Simon Bridge @haruspex

 

[ehild]

Try http://okphysics.com/6-46-image-formed-by-a-silvered-plano-convex-lens/

 

[haruspex]

from there it will diverge (refract again) towards the incident side only.
.

Are you sure? In your diagram, make sure you draw quite modest refractions so that you don't confuse yourself.

 

[sarthak sharma]

Are you sure? In your diagram, make sure you draw quite modest refractions so that you don't confuse yourself.

@haruspex i think i kind of get what you want to say that angle of refraction are not very much large...
so the diagram given above by @ehild would be an ideal diagram
and going by it it is pretty much clear that the incident rays converge on the same side on a point on the pricipal axis and hence it acts like a Concave Mirror
confirm it if you agree...

 

[haruspex]

@haruspex i think i kind of get what you want to say that angle of refraction are not very much large...
so the diagram given above by @ehild would be an ideal diagram
and going by it it is pretty much clear that the incident rays converge on the same side on a point on the pricipal axis and hence it acts like a Concave Mirror
confirm it if you agree...

Yes.