Download App

RAY OPTICS AND OPTICAL INSTRUMENTS — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsRAY OPTICS AND OPTICAL INSTRUMENTS3 Marks
Question
Explain two  main important points for astronomical telescope.
✓

Answer

→The main considerations with an astronomical telescope are its light gathering power and its resolution (or resolving power).
→In objective lens light gathering power depends on the area of the objective.
→With larger diameters, fainter objects can be observed. The resolving power or the ability to observe two objects distinctly also depends on the diameter of the objective. So the desirable aim in optical telescope is to make them with objective of large diameter.
→The largest lens objective in use has a diameter of 40 inch (~ 1.02 m). It is at the Yerks observatory in Wisconsin, USA.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from RAY OPTICS AND OPTICAL INSTRUMENTS→RAY OPTICS AND OPTICAL INSTRUMENTS — all question types→Physics STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

Consider the situation of the previous problem. A particle having charge q and mass m is projected from the point Q in a direction going into the plane of the diagram. It is found to describe a circle of radius r between the two plates. Find the speed of the charged particle.
→
$A 1000 MW$ fission reactor consumes half of its fuel in $5.00 y$. How much $^{235}_{92}\text{U}$ did it contain initially? Assume that the reactor operates $80\%$ of the time, that all the energy generated arises from the fission of $^{235}_{92}\text{U}$ and that this nuclide is consumed only by the fission process.
→
What are isotopes? Explain with an example how the average mass can be obtained from the relative proportions of different isotopes of the same element.
→
Drive the formula of electric field for points on the equatorial plane at distance $r$ from the centre of electric dipole.
→
Obtain essential expression for balanced position of Wheatstone Bridge.###Explain the principle of Wheatstone Bridge. How can we find the resistance of any resistor using this principle?
→
Find the radius of gyration of a circular ring of radius $r$ about a line perpendicular to the plane of the ring and passing through one of its particles.
→
A large conducting plane has a surface charge density $1.0\times10^{-4}\text{Cm}^{-2}.$ Find the electrostatic energy stored in a cubical volume of edge 1.0cm in front of the plane.
→
An electric bulb is designed to operate at 12 volts DC. If this bulb is connected to an AC source and gives normal brightness, what would be the peak voltage of the source?
→
A person travels on a spaceship moving at a speed of $\frac{5\text{c}}{13}$
  1. Find the time interval calculated by him between the consecutive birthday celebrations of his friend on the earth.
  2. Find the time interval calculated by the friend on the earth between the consecutive birthday celebrations of the traveller.
→
An equiconvex lens of focal length $'f\ '$ is cut into two identical plane convex lenses. How will the power of each part be related to the focal length of the original lens? A double convex lens of $+5D$ is made of glass of refractive index $1.55$ with both faces of equal radii of curvature. Find the value of its radius of curvature.
→