(a) Which optical instrument shows arrangement of lenses as figure?(b) Write in brief the working of this optical instrument.(c) How can we get different magnifications in this optical instrument?(d) Draw the figure again and label it properly.
Answers
a)telescope
b)A telescope is an optical instrument that makes distant objects appear magnified by using an arrangement of lenses or curved mirrors and lenses, or various devices used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation.
c)The telescope is focused correctly for viewing objects at the distance for which the angular magnification is to be determined and then the object glass is used as an object the image of which is known as the exit pupil.
d) what is the figure
a) A refracting telescope
b) Object lens collect the light coming from the distance object and forms the image. The image acts as an object for the eyepiece which forms the final image
c) By use of eyepiece with different focal lengths
Explanation:
a) An optical telescope which uses a lens to form an image is a refracting telescope. Originally used in spy lenses and astronomical telescopes, the refracting telescope design is now used for long focus camera lenses.
b) Refracting telescopes operate with the use of two lenses in order to focus light and demonstrate how the object is closer it is to you than it actually is. Both lenses are in a 'convex' shape. Convex lenses work by bending light inwards . That's why the image looks smaller.
c) Eyepieces that used with refractors, have a wide range of applications and give observers with the capability to choose the magnification of their instruments. The magnification, also called the magnification power, is determined by the distinguishing of the focal length of the object/ by the focal length of the eyepiece.
