A radio receiver is placed at the focal point.As in optical telescope, the incident radio waves are reflected by these dishes and converge at the focus.The radio telescope is made from one or more dishes of a particular parabolic shape.Explain the construction of a radio telescope. Such a telescope is also called a refracting telescope.ī.The lens closer to the eye is called the eyepiece which uses the light collected by the objective lens and produces a large image of the source.The lens facing the object is called the objective lens which is made as large as possible to collect the maximum amount of light coming from a heavenly object.The Galileo’s telescope is made up of two or more convex lenses.Explain the construction of Galileo’s telescope. They pass through the eyepiece and we get a magnified image of the source.Ī.As a result, they get focused at a point lying on the perpendicular to the axis of the telescope’s cylinder.Before these reflected rays converge at the focus, they are deflected again by a small plane mirror.

Light rays coming from space are reflected by the concave mirror.

(a) The Newtonian telescope (Reflecting telescope) Explain the working of the above telescope. What other type of telescope uses a curved mirror?Į. Which type of mirror does the telescope use?ĭ. What type of telescope is shown in the figure?ī. Study the figure and answer the following questions:Ī.

A refracting telescope can be made using two or more lenses.ĥ.

A Cassegrain telescope can be made using a convex mirror, concave mirror and a lens.

A Newtonian telescope can be made using a concave mirror, plane mirror and a lens.

Which type of telescopes can be made using a concave mirror, convex mirror, plane mirror, and a lens? Draw diagrams of these telescopes.

To get rid of all the above problems completely, the telescope is placed above the earth’s atmosphere, in space.Ĥ.

To reduce these problems, optical telescopes are situated on top of mountains, in uninhabited places.

During the night, city lights and cloudy weather cause difficulties.

Because of sunlight, we cannot use optical telescopes during the day.

Due to changes in atmospheric temperature and pressure light rays change their path.

The intensity of visible light coming from a heavenly body decreases due to absorption as it passes through the Earth’s atmosphere.What are the difficulties in using ground-based optical telescopes? How are they overcome? The biggest optical telescope in India is situated at ………………….….ģ. The first scientist to use a telescope for space observations ………………….….Į. A certain X-ray telescope is named after scientist ………………….….ĭ. The wavelength of visible light is between ………………….…. Fill in the blanks with the proper words.Ī. Maharashtra State Board Class 9 Science Solutions Chapter 18 Observing Space: TelescopesĬlass 9 Science Chapter 18 Observing Space: Telescopes Textbook Questions and Answersġ. Balbharti Maharashtra State Board Class 9 Science Solutions Chapter 18 Observing Space: Telescopes Notes, Textbook Exercise Important Questions and Answers.

Science telescope drawing