Chhattisgarh Board Solutions for Chapter: Light: Reflection & Refraction at Spherical Surfaces, Exercise 2: Exercise

The focal length of a concave mirror is $12 \mathrm{cm}$. If the object is placed at focus, where will the image be formed? 

The focal length of a convex lens is $15 \mathrm{cm}$. Where should be the object placed to obtain a real image $3$ times magnified. 
 

The focal length of a concave lens is $30 \mathrm{cm}$. What will be the position and size of the image if a $30 \mathrm{cm}$ long object is placed at the focus. 
 

For an object kept at $30 \mathrm{cm}$ from a concave lens, the magnification achieved in $\frac{2}{3}$. What is the focal length of lens? 

For a convex lens of focal length $50 \mathrm{cm}$, what is the position of image if the object is placed at a distance of $25 \mathrm{cm}$ from the optical centre?

For a convex lens of focal length $50 \mathrm{cm}$, what is the position of image if the object is placed at a distance of $75 \mathrm{cm}$ from the optical centre?

What is the focal length of a lens (in centimetres) whose power is $+1.5 \mathrm{D}$?

What is the power (in Dioptre) of a concave lens of focal length $20 \mathrm{cm}$?