kaplan mirror and lens q practice test

[2010premed]

---

Members don't see this ad.

A converging lens has a focal length of 8cm. If the object is 10cm to the left of the lens, what are the position of the image formed and the magnification of the lens?

A: 40cm to the right of the lens and 4X

I get the image distance to be 40cm, after that, how do you know which side it's on? Kaplan says since it's +, then it's on the "real side" how do you know which side is real?

 

[Rabolisk]

When dealing with lenses, the real side is the side opposite of the object. With mirrors, the real side is the same side as the object. This makes sense because light passes through lens, while it is reflected by mirrors.

 

[2010premed]

thank you!