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1. An object is placed 20 cm in front of a concave mirror of focal length 40 cm.

ID: 1865589 • Letter: 1

Question

1. An object is placed 20 cm in front of a concave mirror of focal length 40 cm. Calculate the image distance and the magnification. An object is placed 25 cm in front of a convex mirror of focal length 30 cm. Calculate the image distance and the magnification. 2. An object of size 5 cm is kept at a distance of 25 cm from the optical center of a converging lens of focal length 10cm. Calculate the distance of the image from the lens and size of the image. 3. 4. A 2.25-cm-tall object is 8.5 cm to the left of a convex lens of 5.5-cm focal length. Find the image position and height. A concave makeup mirror is designed so that a person 25 cm in front of it sees an upright image magnified by a factor of 2. What is the radius of curvature of the mirror? 5.

Explanation / Answer

here,

1)

the object distance , do = 20 cm

the focal length of the mirror , f = 40 cm

let the image distance be di

using the mirror formula

1/f = 1/di + 1/do

1/40 = 1/di + 1/20

solving for di

di = - 40 cm

the image distance is - 40 cm

the magnification , m = -di/do

m = - ( - 40)/20

m = 2