Question

A lens of focal length 10 cm is being used by a student in the laboratory as a magnifying glass. His least distance v of distant vision is 25 cm. What magnification is the student getting

Answer 1

apply lens formula to get u

1/v-1/u=1/f

v= -25 cm

f=10 cm

1/u=1/v-1/f

=-1/25-1/10

=-7/50

u=-50/7 cm

v/u = m

-25 /(-50/7)

m=3.5 .......approx

hope it helps!