General Knowledge - Basic General Knowledge - Discussion

Discussion Forum : Basic General Knowledge - Section 1 (Q.No. 57)
For seeing objects at the surface of water from a submarine under water, the instrument used is
Answer: Option
No answer description is available. Let's discuss.
15 comments Page 1 of 2.

Bhanu said:   3 years ago
Good information, thanks all.

Amali said:   3 years ago
What is kaleidoscope and sprectoscope?

Amali said:   3 years ago
What is periscope?

Prajapati said:   6 years ago
Kaleidoscope is a circle of mirrors containing loose, colored objects such as beads or pebbles and bits of glass. As the viewer looks into one there are three rectangular lengthwise mirrors. Setting the mirrors at a 45-degree angle creates eight duplicate images of the objects, six at 60 deg, and four at 90 degrees.

As the tube is rotated, the tumbling of the coloured objects presents the viewer with varying colours and patterns. Any arbitrary pattern of objects shows up as a beautiful symmetrical pattern created by the reflections in the mirrors. A two-mirror model yields a pattern or patterns isolated against a solid black background, while a three-mirror (closed triangle) model yields a pattern that fills the entire field.

Ganesh Thigari said:   6 years ago
Periscopes allow a submarine, when submerged at a relatively shallow depth, to search visually for nearby targets and threats on the surface of the water and in the air. When not in use, a submarine's periscope retracts into the hull.

A submarine commander in tactical conditions must exercise discretion when using his periscope, since it creates a visible wake (and may also become detectable by radar[citation needed]), giving away the sub's position.

Ambika said:   7 years ago
Spectroscope also detects the objects under the surface of the water.

Pari Suri said:   8 years ago
what is kaleidoscope? What is the use of kaleidoscope?

Bilal said:   1 decade ago
Thank you Mr Amar

Amar Kumar said:   1 decade ago
A kaleidoscope is a cylinder with mirrors containing loose, colored objects such as beads or pebbles and bits of glass. As the viewer looks into one end, light entering the other creates a colorful pattern, due to the reflection off of the mirrors. Coined in 1817 by Scottish inventor Sir David Brewster.

A periscope (or berinscope) is an instrument for observation from a concealed position. In its simplest form it consists of a outer case with mirrors at each end set parallel to each other at a 45-degree angle. This form of periscope, with the addition of two simple lenses, served for observation purposes in the trenches during World War I. Military personnel also use periscopes in some gun turrets and in armoured vehicles.

A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light). The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s (the 17th century) , using glass lenses. They found use in terrestrial applications and astronomy.

A spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum.

Noor said:   1 decade ago
What is use kaleidoscope, periscope, telescope and spectroscope?

Post your comments here:

Your comments will be displayed after verification.