Question

A concave spherical mirror has a radius of curvature of 22 cm. Locate the images for object distances as given below. In each case, state whether the image is real or virtual and upright or inverted, and find the magnification. (If an answer does not exist, enter DNE. If an answer is infinity, enter INFINITY.) (a) p=11 cm image distance image orientation -Select- magnification 7 x cm DNE (b) p- 22 cm image distance image orientation magnification 22 cm real and inverted -1 (c) p=51 cm image distance image orientation Select magnification cm

Answer 1

for first question

we have radius of curvature R=22 cm

we know that focal length

f=R/2=22/2=11 cm

a) from lens eqn we have,

1/q=1/f-1/p=1/11-1/11=11-11/11=0/11

q*0=11

q=11/0=$\infty$

so answer image distance=INFINITY

image orientation=No image is formed because the position of the object is at focal point

c) again using the lens eqn

1/q=1/f-1/p=1/11-1/51=51-11/561=41/561

41q=561

q=561/41=13.7 cm

image distance=13.7cm or 14 cm

image orientation=real and inverted ( because image distance came out to be positive and magnification is negative)

magnification is given by

M=-q/p=-13.7/51=-0.268

so M= -0.268 or -0.269 or -0.27