Tag: space travel

Quizzes (7) Questions (83)

Questions Related to space travel

Multiple choice physics observing space: telescopes space research and satellites space travel space exploration and forms of light

While viewing a distant object with telescope a housefly sits on objective lens. Then which of the following is the correct statement :

  1. housefly will be seen enlarged in image

  2. housefly will be seen reduced in image

  3. intensity of image will be decreased

  4. intensity of image will be increased
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When housefly sits on the objective lens, light intensity will fall at objective because housefly will stop the light to fall on the objective. So, intensity of the image is decreased. Hence correct option is C.

Multiple choice physics observing space: telescopes space research and satellites space travel space exploration and forms of light

First adjustment of a spectrometer is :

  1. focusing the distant object

  2. focusing the cross wires

  3. focusing the slit

  4. focusing near objects
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

First we look through the telescope at any light - coloured surface and push the eyepiece in and out until we can see the cross-wires sharply, without straining our eyes, So, first adjustment in a spectrometer is focusing of the cross wires.

Multiple choice physics observing space: telescopes space research and satellites space travel space exploration and forms of light

Large aperture objective is used in telescopes as it helps in

  1. increasing the brightness of image

  2. reducing image size

  3. increasing field of view

  4. increasing intensity by gathering more light
Reveal answer Fill a bubble to check yourself
A,D Correct answer
Explanation

The larger the objective, the more light the telescope collects and increases the brightness of image .

The field of view of the telescope decreases as the aperture increases, but the resolving power increases.
The objective lens of a telescope forms an real image of the night sky, the size of that image is in proportion to the focal length of the objective lens. It increases with increase in size of objective lens.

Multiple choice physics observing space: telescopes space research and satellites space travel space exploration and forms of light

Large astronomical telescopes always use as objective

  1. lens

  2. mirror

  3. combinations of lenses

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Large astronomical telescopes always use combination of lens as objective because
(1)To minimize spherical aberration.
(2)To maximize the amount of light ray entering the telescope.
(3)To optimize the quality of image.
Multiple choice physics observing space: telescopes space research and satellites space travel space exploration and forms of light

In astronomical telescope, the final image is formed at:

  1. the least distance of distinct vision

  2. the focus of objective lens

  3. the focus of the eye lens

  4. beyond the focal length of eyepiece.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In astronomical telescope, the image formed by objective $I _1$ is real and inverted. It is formed at focus of objective lens. $I _1$ is placed between the focal length of eyepiece and the lens. Hence, it forms a virtual image beyond the focal length of eyepiece.

Multiple choice physics observing space: telescopes space research and satellites space travel space exploration and forms of light

In which of the following instruments is final image erect?

  1. Simple mircoscope

  2. Compound mircoscope

  3. Astronimical telescope

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A simple microscope is magnifying glass, an ordinary double convex lens having a short focal length that produces virtual and erect image.

rather a Compound microscope and astronomical telescope produces virtual and final inverted image. hence correct option is A.

Multiple choice physics observing space: telescopes space research and satellites space travel space exploration and forms of light

Large aperture objective is used in telescope. Which of the following is not a function of the objective?

  1. Increasing the brightness of image.

  2. Reducing image size.

  3. Increasing field of view.

  4. Increasing intensity by gathering more light.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Large aperture objective is used in telescope as it can help in increasing the brightness of image, increasing field of view and increasing intensity by gathering more light.

Multiple choice physics observing space: telescopes space research and satellites space travel space exploration and forms of light

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 $3.8\times {10}^{8}\ m.$

  1. $10\ cm$
  2. $12.5\ cm$
  3. $15\ cm$
  4. $17.5\ cm$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The size of the image formed by the objective is given by f * tan(theta), where theta is the angular size of the moon. Angular size = diameter / distance = 3.5e6 / 3.8e8 = 0.00921 radians. Image size = 1900 cm * 0.00921 = 17.5 cm.