The focal length of a simple magnifier is 7.00 cm. Assume the magnifier to be a
ID: 1676455 • Letter: T
Question
The focal length of a simple magnifier is 7.00 cm. Assume the magnifier to be a thin lensplaced very close to the eye. (a) How far in front of the magnifier should anobject be placed if the image is formed at the observer's nearpoint, 25.0 cm in front of her eye?1 cm
(b) If the object is 2.70 mm high,what is the height of its image formed by the magnifier?
2 mm
(a) How far in front of the magnifier should anobject be placed if the image is formed at the observer's nearpoint, 25.0 cm in front of her eye?
1 cm
(b) If the object is 2.70 mm high,what is the height of its image formed by the magnifier?
2 mm
Explanation / Answer
(a) How far in front of the magnifier shouldan object be placed if the image is formed at the observer's nearpoint, 25.0 cm in front of her eye? in cm
f= 7cm
v=25cm u=?using the equation1/u=1/f-1/v=1/7-1/25=>u=9.722cm
(b) If the object is 2.70 mmhigh, what is the height of its image formed by themagnifier?
magnification=m=v/u=25/9.722=2.571pp
so size of the image=m*size of theobject=2.571*2.7=6.9417mm