Question

a convex lens form image at distance of 60 cm from the lens having focal length of 30cm calculate the object distance and power​

Answer 1

Answer:

Expert Answer:

f = +30 cm (convex lens)

v = +60 cm (Since image forms on the other side of the lens)

Use lens formula,

begin mathsize 12px style 1 over straight f space equals space 1 over straight v space minus space 1 over straight u

rightwards double arrow 1 over straight u space equals space 1 over 60 space minus space 1 over 30 space equals space fraction numerator 1 minus 2 over denominator 60 end fraction space equals space fraction numerator negative 1 over denominator 60 end fraction

rightwards double arrow space straight u space equals space minus space 60 space cm end style

Hence, the object is at a distance of 60 cm on the left side of the lens.

begin mathsize 12px style straight m space equals space fraction numerator Image space distance space left parenthesis straight v right parenthesis over denominator Object space distance space left parenthesis straight u right parenthesis end fraction

rightwards double arrow straight m space equals space fraction numerator 60 space cm over denominator negative 60 space cm end fraction space equals space minus 1 space cm end style

The negative sign of m indicates that image is inverted.