The diagram above shows the lens arrangement in
A. compound microscope
B. a binocular
C. an astronomical telescope
D. a periscope
Careful observation of the diagram above shows that rays of light originated from infinity and pass through the objective lens to converge and form a real, inverted, and clear image. This is enough to reveal that this is an astronomical telescope.
Astronomical telescopes are instruments used by astronomers to study distant objects assumed in this case to be at infinity. These telescopes take light rays from a very far planet or star, passing them through the objective lens, and getting them converge as real and inverted, but bold images that can be analyzed.
Now for the right answer to the above question:
- Option A is incorrect. compound microscopes do not take light rays from infinity as shown in the diagram.
- Option B is incorrect. a binocular is an optical device consisting of two telescopes mounted side by side and often used on both eyes to view magnified but upright (not inverted) images of distant objects.
- C is correct. an astronomical telescope takes rays from infinity and converge them into a real but inverted bold image.
- D is not the correct answer. A periscope is simply a combination of mirrors (not lenses) inclined at certain angles in a tube to see objects that are beyond.
You may please note these/this:
- In an astronomical telescope, the focal length of the objective lens is longer than that of the eyes lens.
- That is, the objective lens is wider than the eyes lens.
- A binocular is a combination of two telescopes mounted on both eyes to view distant objects, but the image is usually upright and not inverted as shown in the diagram.
- If you love our answers, you can login to comment and say hi to us at the comment section…
To raise new related questions, click the ASK A QUESTION BOTTON down this page…
/ culled from 2015 JAMB-UTME physics past question 2 /