Question
A simple microscope is rated 5 for a normal relaxed eye. What will be its magnifying power for a relaxed farsighted eye whose near point is 40cm?
✓
Answer
The simple microscope has magnification of 5 for normal relaxed eye (D = 25cm).Because, the eye is relaxed the image is formed at infinity (normal adjustment)
So, $\text{m}=5=\frac{\text{D}}{\text{f}}=\frac{25}{\text{f}}\Rightarrow\text{f}=5\text{cm}$
For the relaxed farsighted eye, $\text{D} = 40\text{cm}$
So, $\text{m}=\frac{\text{D}}{\text{f}}=\frac{40}{5}=8$
So, its magnifying power is 8X.
So, $\text{m}=5=\frac{\text{D}}{\text{f}}=\frac{25}{\text{f}}\Rightarrow\text{f}=5\text{cm}$
For the relaxed farsighted eye, $\text{D} = 40\text{cm}$
So, $\text{m}=\frac{\text{D}}{\text{f}}=\frac{40}{5}=8$
So, its magnifying power is 8X.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A small pin fixed on a table top is viewed from above from a distance of 50cm. By what distance would the pin appear to be raised if it is viewed from the same point through a 15 cm thick glass slab held parallel to the table? Refractive index of glass = 1.5. Does the answer depend on the location of the slab?
On changing a current carrying coil of N turns and R radius into a straight wire, how many times the magnetic field at distance R will be than at the magnitude at the center of the coil?
The susceptibility of magnesium at $300K$ is $1.2 \times 10^{-5}.$ At what temperature will the susceptibility increase to $1.8 \times 10^{-5}$?
→Two unequal resistances $R_1$ and $R_2$ are connected across two identical batteries of emf $\varepsilon$ and internal resistance $r$. Can the thermal energies developed in $R_1$ and $R_{2}$ be equal in a given time. If yes, what will be the condition?
→A steel wire and a copper wire of equal length and equal cross-sectional area are joined end to end and the combination is subjected to a tension. Find the ratio of.
→- The stresses developed in the two wires.
- The strains developed. $Y$ of steel $= 2 \times 10^{11}N/m^2. Y$ of copper $= 1.3 \times 10^{11}N/m^2.$
A source of sound with adjustable frequency produces $2$ beats per second with a tuning fork when its frequency is either $476\ Hz$ or $480\ Hz.$ What is the frequency of the tuning fork?
→A 44 m H inductor is connected to 220 V, 50 Hz ac supply. Determine the rms value of the current in the circuit.
State Bohr's quantization condition of angular momentum. Calculate the shortest wavelength of the Bracket series and state to which part of the electromagnetic spectrum does it belong.
Answer the following questions: Magnifying power of a simple microscope is inversely proportional to the focal length of the lens. What then stops us from using a convex lens of smaller and smaller focal length and achieving greater and greater magnifying power?
The susceptibility of annealed iron at saturation is 5500. Find the permeability of annealed iron at saturation.