The angular magnification of an astronomical telescope in normal adjustment is 36, and the diameter of the objective lens is 72mm. (Notice that this is the same configuration as a beam expander, see figure below which is NOT to scale. a. What is the minimum diameter of the eyepiece required to collect all the light entering the objective lens from a distant point source on the axis of the instrument? b. In order to use the thin lens approximation, the radius of curvature of the lens should be larger than the diameter of the lens itself. For a radius of curvature of 720mm for both sides of the objective lens (one is negative, one is positive), and an index of refraction of the objective glass of 1.5, what is the focal length of the Objective Lens? c. What is the focal length of the eyepiece given the focal length of the objective lens? d. What is the minimum length of the telescope? (i.e. the total distance between the eyepiece and the objective lenses).
Ray Optics
Optics is the study of light in the field of physics. It refers to the study and properties of light. Optical phenomena can be classified into three categories: ray optics, wave optics, and quantum optics. Geometrical optics, also known as ray optics, is an optics model that explains light propagation using rays. In an optical device, a ray is a direction along which light energy is transmitted from one point to another. Geometric optics assumes that waves (rays) move in straight lines before they reach a surface. When a ray collides with a surface, it can bounce back (reflect) or bend (refract), but it continues in a straight line. The laws of reflection and refraction are the fundamental laws of geometrical optics. Light is an electromagnetic wave with a wavelength that falls within the visible spectrum.
Converging Lens
Converging lens, also known as a convex lens, is thinner at the upper and lower edges and thicker at the center. The edges are curved outwards. This lens can converge a beam of parallel rays of light that is coming from outside and focus it on a point on the other side of the lens.
Plano-Convex Lens
To understand the topic well we will first break down the name of the topic, ‘Plano Convex lens’ into three separate words and look at them individually.
Lateral Magnification
In very simple terms, the same object can be viewed in enlarged versions of itself, which we call magnification. To rephrase, magnification is the ability to enlarge the image of an object without physically altering its dimensions and structure. This process is mainly done to get an even more detailed view of the object by scaling up the image. A lot of daily life examples for this can be the use of magnifying glasses, projectors, and microscopes in laboratories. This plays a vital role in the fields of research and development and to some extent even our daily lives; our daily activity of magnifying images and texts on our mobile screen for a better look is nothing other than magnification.
The angular magnification of an astronomical telescope in normal
adjustment is 36, and the diameter of the objective lens is 72mm. (Notice that this is
the same configuration as a beam expander, see figure below which is NOT to scale.
a. What is the minimum diameter of the eyepiece required to collect all the light
entering the objective lens from a distant point source on the axis of the
instrument?
b. In order to use the thin lens approximation, the radius of curvature of the lens
should be larger than the diameter of the lens itself. For a radius of curvature of
720mm for both sides of the objective lens (one is negative, one is positive), and
an index of refraction of the objective glass of 1.5, what is the focal length of the
Objective Lens?
c. What is the focal length of the eyepiece given the focal length of the objective
lens?
d. What is the minimum length of the telescope? (i.e. the total distance between
the eyepiece and the objective lenses).
Trending now
This is a popular solution!
Step by step
Solved in 4 steps
