Английский язык. Ч.3 (Units 9,10). Ильичева Н.А - 17 стр.

A. … contains two converging lenses located at opposite ends of a long tube.
The lens closest to the object is called the objective lens and forms a real image
of the distant object. Although this image is smaller than the original object, it
subtends a greater angle and is very close to the second lens, called the eyepiece,
which acts as a magnifier.


B. … is used to produce magnified images of objects. The angle that an object
subtends at the eye appears larger when it is used and more detail can be seen.


C. … is an instrument that separates a source of light into its respective
frequencies or wavelengths.


D. … has been placed in orbit above the Earth’s atmosphere, so its resolution is
not limited by turbulence in the atmosphere. Its objective diameter is 2,4 m.


E. … allow only the vertical component of the light to pass, and the horizontal
component is blocked out, which reduces the glare.


F. … uses a concave mirror as the objective, since a mirror has only one surface
to be ground (the construction and grinding of large lenses is very difficult).
Normally, the eyepiece lens or mirror is removed so that the real image formed
by the objective mirror can be recorded directly on film.


G. … is used to magnify objects that are very far away. In most cases, the object
may be considered to be an infinity.


H. … is a device using a diffraction grating or a prism to separate different
wavelengths and equipped with a scale for measuring them.


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