Question

An object is placed at a distance of 40cm in front of a
concave lens of focal length of 25cm. Find the image
distance. What will be its nature?​

Answer 1

Answer:

Object distance= -40 cm (Object distance is always negative)

focal length= -25 cm (In a concave lens focal length is always negative as well    as the power)

Using lens Formula:

1/v-1/u=1/f

1/v+1/40= -1/25

1/v= -1/25-1/40

1/v= -40-25/25*40

1/v= -200/13

1/v= -15.38 cm

In a concave lens the nature of the image is always virtual,erect and diminished.