The lens formula relating the image distance,p,to the focal length,f,and object distance,s,is The magnification of a lens is
-A magnifying glass with focal length 15 cm is placed 10 cm above a stamp.The image of the stamp is located
A)30 cm above the magnifying glass.
B)30 cm below the magnifying glass.
C)30 cm above the stamp.
D)30 cm below the stamp.
E)15 cm from the magnifying glass.

Question

The lens formula relating the image distance,p,to the focal length,f,and object distance,s,is  The magnification of a lens is 
-A magnifying glass with focal length 15 cm is placed 10 cm above a stamp.The image of the stamp is located
A)30 cm above the magnifying glass. 
B)30 cm below the magnifying glass. 
C)30 cm above the stamp. 
D)30 cm below the stamp. 
E)15 cm from the magnifying glass.

Quizplus · Accepted Answer

The lens formula is 1/f = 1/v - 1/u. Here, f = 15 cm and u = -10 cm (since the object is on the same side as the incoming light). Solving gives v = 30 cm, meaning the image is 30 cm on the opposite side of the lens, or 30 cm below the magnifying glass.

The Lens Formula Relating the Image Distance,p,to the Focal Length,f,and