An object is placed at a distance of 60 cm from a converging lens with a focal length of 20 cm. What is the magnification of the lens?
To find the magnification of a lens, we can use the lens formula:
1/f = 1/v - 1/u
Where:
f is the focal length of the lens
v is the image distance
u is the object distance
In this case, the object distance is given as 60 cm (u = 60 cm) and the focal length is given as 20 cm (f = 20 cm).
To find the image distance, we can rearrange the lens formula:
1/v = 1/f + 1/u
Substituting the values, we have:
1/v = 1/20 + 1/60
1/v = 3/60 + 1/60
1/v = 4/60
v = 60/4
v = 15 cm
Now, we can find the magnification (m) using the formula:
m = -v/u
Substituting the values, we have:
m = -15/60
m = -1/4 or -0.25
Therefore, the magnification of the lens is -0.25. The negative sign indicates that the image is inverted.