Observing space: telescopes - class-VIII
Description: observing space: telescopes | |
Number of Questions: 81 | |
Created by: Neema Pandya | |
Tags: universe the sun, the stars that crowd the sky electromagnetic waves and communication system search of life outside earth ray optics and optical instruments observing space: telescopes lens lenses space travel physics geography |
The angular resolution of a 10cm diameter telescope at a wavelength of $5000 A^0$ is of the order of -
An observer looks at a distant tree of height $10$ m with a telescope magnifying power of $20$. To the observer, the top appears
The focal length of eye lens and object lens of a telescope is 4 mm and 4 cm respectively. If final image of an far object is at $\infty $. Then the magnifying power and length of the tube are :
Which of the following is correct about astronomical telescope?
Telescopic aids are used:
Why is it advised to used telescope at night?
Which of the following is true for a telescope?
In an astronomical telescope the focal lengths of objective and eyepiece should respectively be :
The image formed by the telescope in normal adjustment position is at :
While viewing a distant object with telescope a housefly sits on objective lens. Then which of the following is the correct statement :
First adjustment of a spectrometer is :
A terrestrial telescope is used to view the details of the distant objects on the earth.
Large aperture objective is used in telescopes as it helps in
Large astronomical telescopes always use as objective
In astronomical telescope, the final image is formed at:
In which of the following instruments is final image erect?
Large aperture objective is used in telescope. Which of the following is not a function of the objective?
A gain telescope in an observatory has an objective of focal length $19\ m$ and an eye-piece of focal length $1.0\ cm$. What is the diameter of the image of moon formed by the objective in normal adjustment? The diameter of moon is $3.5\times {10}^{6}\ m$ and the radius of the lunar orbit round the earth is $3.8\times {10}^{8}\ m.$
A telescope of objective lens diameter $2m$ uses light of wavelength $5000 \mathring {A}$ for viewing starts. The minimum angular separation between two stars whose image is just resolved by their telescope is:
A tower $100m$ tall at a distance of $3$km is seen through a telescope having objective of focal length $140$cm and eyepiece of focal length $5cm$. Then the size of final image if it is at $25$cm from the eye?
The angular resolution of a radio telescope is to be ${ 0.100 }^{ 0 }$ when the incident beam of wavelength $ 3.00mm$ is used. What is minimum diameter required for the telescope's receiving dish?
The focal lengths of the objective and eye lens of telescope are respectively $200\ cm$ and $5\ cm$. The maximum magnifying power of the telescope will be.
An observer looks at a distant tree
of height $10$ m with a
telescope of magnifying power of $20$. To the
observer the tree appears :
.
The angular resolution of a $10cm$ diameter telescope at a wavelength of $5000A$ is of the order of
In a terrestrial telescope, the telescope, the focal length of objective is 90 cm of inverting lens is 5 cm and of eye lens is 6 cm. If the final image is at 3 cm, then the magnification will be
The focal lengths of the objective and eye plece of astronomical telescope are $100cm$ and $2cm$ respectively. The magnitude of magnifying power of telescope for adjustment is
The focal length of an objective of a telescope is 3 meter and diameter 15 cm. Assuming for a normal eye, the diameter of the pupil is 3 mm for its complete use, the focal length of eye piece must be
The diameter of the lens of a telescope is $1.22m$. The wavelength of light of $5000\mathring {A}$. The resolving power of the telescope is _____
An astronomical telescope and a Galilean telescope use identical objective lenses. They have the same magnification, when both are in normal adjustment. The eyepiece of the astronomical telescope has a focal length f.
A terrestrial telescope is made by introducing an erecting lens of focal length, $f$, between the objective and eyepiece lens of an astronomical telescope. This causes the length of telescope tube to increase by an amount equal to
The objective of a telescope has a focal length of $1.2\ m$. It is used to view a $10.0\ m$ tall tower $2\ km$ away. What is the height of the image of the tower formed by the objective.
In an astronomical telescope, the distance between the objective and the eyepiece is 36 cm and the final image is formed at infinity. The focal length $f _0$ of the objective and the focal length $f _e$ of the eyepiece are
The device used to observe stars and other heavenly bodies is
A telescope gives an .............. (inverted / erect) and ........ (enlarged/diminished) image of a distant object. Choose the correct alternative.
State whether true or false :
A simple telescope has
Match List-I with List- II and select the answer using the codes given below the lists:
List-I | List-II | ||
---|---|---|---|
A. | Microscope | 1. | To see objects on the surface by an observer in a trench |
B. | Telescope | 2. | To see small objects |
C. | Periscope | 3. | To see distant objects |
D. | Camera | 4. | To take photographs of objects |
The focal length of eye lens and object lens of a telescope is 4 mm and 4 cm respectively. If final image of an far object is at $\displaystyle \infty $. Then the magnifying power and length of the tube are:
An astronomical telescope has an eyepiece of focal length $5 cm$. If magnification produced is $14$ in normal adjustment, then what is the length of telescope?
Why is it advised to use telescope in a clear sky?
A telescope:
A planet is observed by an astronomical reflecting telescope having an objective of focal length 16 m and an eye - piece of focal length 2 cm.
Telescopes make the far objects appear:
The anguThe angular resolution of 10cm diameter telescope at a wavelength of $5000nm$ is of order of the
The optical length of an astronomical telescope with magnifying power of 10, for normal vision is 44cm. What is focal length of the objective?
The final image formed by an astronomical telescope is:
What is the magnifying power of a telescope whose objective and eye - piece have focal length 180 cm and 3 cm respectively?
Salyut 6 and Salyut 7, were built with:
The space stations so far launched are broadly classified into two types:
Salyut and Skylab were built:
Which of the following is cannot be considered as the use of space stations?
The number of wavelengths in the visible spectrum is :
Choose the correct answer from the alternatives given.
Which of the following ray are not electromagnetic waves
The image of a distant object as seen through an astronomical telescope is
The large aperture of telescope are used for
The length of an astronomical telescope for normal vision is _______.
In which of the following instruments is final image erect?
In which of the following instruments is the final image inverted?
The final image formed by an astronomical telescope is
For the astronomical telescope, the focal length of objective lens is ${f} {o}$ and the eye piece lens is ${f} _{e}$. Then the tube length of the telescope is ____
In an astronomical telescope, the intermediate image is
Magnifying power of an astronomical telescope is 15. Then ratio of the focal length of the objective to the focal length length of the eye piece is
In a terrestrial telescope the focal length erecting lens is $20cm$. The length of the telescope $96cm$ . If the magnifying power of the telescope $10$. Then the focal length of eye -piece and objective are respectively
The aperture of the largest telescope in the world is $5 m,$ if the separation between the Moon and the Earth is $4 \times 10^5 km$ and the wavelength of the visible light is $5000 \overset {o}{A}$ then the minimum separation between the objects on the surface of the Moon which can be just resolve is approximately
If an astronomical telescope has objective and eye-pieces of focal length 200 cm and 4 cm respectively,then the magnifying power of the telescope for the normal vision is:
Focal lengths of the objective lens and eye-piece of an astronomical telescope are $2m$ and $0.05m$. Find the length of telescope in normal adjustment.
The diameter of moon is $3.5\times{10}^{3}km$ and its distance from the earth is $3.8\times{10}^{5}km$. The focal length of the objective and eyepiece are $4m$ and $10cm$ respectively. The angle subtended by the diameter of the image of the moon will be approximately
The magnifying power an astronomical telescope for normal adjustment is -
If for a given telescope $D = 22 \,mm$ and $\lambda = 6 \times 10^{-7}m$, then the minimum value of the angle subtended by two stars that could be resolved is approximately:
The focal length of objective of an astronomical telescope is $1m$. If the magnifying power of telescope is $8$, then what is length of telescope for relaxed eye?
The diameter of the lens of a telescope is 1.22 m., the wavelength of light is $5000{A^0}$ the resolution power of the telescope is
If an object subtend angle of $2^0$ at eye when seen through telescope having objective and eyepiece of focal length $f _0=60cm$ and $f _e=5cm$ respectively than angle subtend by image at eye piece will be
An astronomical telescope has an eye piece of focal length $5\ cm$. If magnification produced is 14 in normal adjustment, then calculate the length of the telescope.
A narrow vertical slit of width 2 mm is placed in front of a telescope.This setup is used to observe a car with its head light 1.2 m apart. The diameter of the objective of the telescope is 2 cm and the wavelength of light from the headlights is $ 5000 \mathring { A } $. The distance of the car when the two headlights of the car are just resolved is:-
The ratio of resolving power of telescope, when lights of wavelength $4400\overset{o}{A}$ and $5500\overset{o}{A}$ are used, is _________.
The diameter of the moon is $3.5\times 10^{3} km$ and its distance from the earth is $3.8\times 10^{5} km$. The diameter of the image of the moon seen by a telescope having focal length of the objective and eye-piece as $400\ cm$ and $10\ cm$ respectively will be
The magnification produced by an Astronomical telescope in normal
A telescope has a objective of focal length $60\, cm$ and an eye-piece of focal length $5\, cm$. The least distance of distinct vision is $25\, cm$. The telescope is focussed for distinct vision on a scale of $300\, cm$ away. The separation between the objective and the eye-piece is
The length of an astronomical telescope for normal vision (relaxed eye) will be:
The focal length of the objective of a terrestrial telescope is $80cm$ and it is adjusted for parallel rays, then its power is $20$. If the focal length of erecting lens is $20cm$, then full length of the telescope will be
An astronomical refractive telescope has an objective of focal length 20 m and an eyepiece of focal length 2 cm. then