Exercises

Define and describe magnifying power of an optical instrument. How does it differ from linear or lateral magnification?

Derive an expression for magnifying power of a simple microscope. Obtain its minimum and maximum values in terms of its focal length.

A rectangular sheet of length $30 \mathrm{cm}$ and breadth $3 \mathrm{cm}$ is kept at $45 \mathrm{cm}$ from pole on the principle axis of a concave mirror of focal length $30 \mathrm{cm}$. Draw the image formed by the mirror on the same diagram as far as possible on scale. 

What is a terrestrial telescope and an astronomical telescope? 

A car uses a convex mirror of curvature $1.2 \mathrm{m}$ as its rearview mirror. A minibus of cross-section $2.2 \mathrm{m}\times 2.2 \mathrm{m}\times 6.6 \mathrm{m}$ is away from the mirror. Estimate the image size.

Derive the expressions for the magnifying power and the length of a compound microscope using two convex lenses.

A glass slab of thickness $2.5 \mathrm{cm}$ having refractive index $5/3$ is kept on ink spot. A transparent beaker of very thin bottom containing water of refractive index $4/3$ up to $8 \mathrm{cm}$ is kept on the glass block. calculate apparent depth of the ink spot when seen from the outside air . 

A convex lens held at some distance above $6 \mathrm{cm}$ long pencil produces its image of same size. On shifting the lens by a distance equal to its focal length, it again produces the image of the same size as earlier. Determine the image size.