Question

A student wants to project the image of a candle flame on a screen 90 cm in front of a mirror by keeping the flame at a distance of 15 cm from its pole.; (a) Suggest the type of mirror he should use.; (b) Determine the liner magnification in this case.; (c) Find the distance between the object and its image.; (d) Draw ray diagram to show the image formation in this case.(All India - 2014)

Answer 1

Answer:

a. Concave mirror

b. m = -6

c. -75 cm

d. Refer to the attachment

Explanation:

a. Since v is -ve, the image formed is real. A convex mirror can't form a real image in any case. Hence, he should use a concave mirror.

b.

v = -90 cm

u = -15 cm

m = -v/u = -(-90)/(-15) = -6

c.

Distance between object and image = v - u

= -90 - (-15)

= -90 + 15

= -75 cm

d. 1/f = 1/v + 1/u = -1/90 - 1/15 = -1 - 6/90 = -7/90

f = -90/7

f = - 12.85 cm

Refer to the attachment.