Question

An object is placed 10 cm from a convex lens of focal length 20 cm. What is the lateral magnification of the object?

A) 0.50
B) 1.0
C) 1.5
D) 2.0
E) 2.5

Answer 1

D 2

Step-by-step explanation:

Given that

Distance of the object, u = 10 cm

Focal distance of the object, f = 20 cm

Then again, we know from the lens formula that

1/f = 1/u + 1/v

Then we solve for the distance of the image, v

1/20 = 1/10 + 1/v

1/v = 1/20 - 1/10

1/v = (1 - 2) /20

1/v = -1/20

v = -20 cm

Lateral magnification is given as

m = -v/u,

So we input our values

m = - -20/10

m = 20/10

m = 2