General Principles in the Working of Telescope, Microscope
General Principles in the Working of Telescope, Microscope MCQ Questions
1.
Who invented the telescope?
ANSWER :
C. Hans Lippershey
Approach
The question asks about the inventor of the telescope. To answer this, we need to recall the historical figures associated with the invention and early development of the telescope.
Step-by-step
- Identify the key individuals often credited with the invention or significant improvements of the telescope.
- Recall that while Galileo Galilei popularized and made significant astronomical discoveries with the telescope, he was not its inventor.
- Remember that the first known patent application for a telescope was filed by a Dutch spectacle maker.
- Connect this information to the given options to find the correct inventor.
Correct Option:
C) Hans Lippershey — Hans Lippershey, a German-Dutch spectacle maker, is widely credited with inventing the telescope in 1608. He applied for a patent for his "device for seeing faraway things as though nearby" in the Netherlands, though his patent was ultimately denied because similar devices were already being developed.
Incorrect Options
- A) Galileo Galilei — Galileo Galilei significantly improved upon the design of the telescope and was the first to use it for astronomical observations, leading to groundbreaking discoveries. However, he did not invent the telescope itself; he built his own versions after hearing about Lippershey's invention.
- B) Isaac Newton — Isaac Newton invented the reflecting telescope in 1668, which used mirrors instead of lenses to form images. This was a significant advancement, but it occurred decades after the initial invention of the refracting telescope.
- D) Edwin Hubble — Edwin Hubble was a prominent American astronomer who made crucial discoveries in the early 20th century, including the expansion of the universe and the existence of other galaxies beyond the Milky Way. He used large, powerful telescopes (like the Hooker Telescope at Mount Wilson Observatory), but he was not involved in the invention of the telescope.
2.
What is the primary function of a telescope?
ANSWER :
A. Magnify objects
Approach
The question asks for the primary function of a telescope. We need to recall the basic purpose of this optical instrument.
Step-by-step
- A telescope is an optical instrument designed to make distant objects appear nearer, containing an arrangement of lenses or curved mirrors and lenses, by which rays of light are collected and focused and the resulting image magnified.
- Its main purpose is to gather light from distant objects and bring them into focus, making them appear larger and brighter than they would to the naked eye. This process is known as magnification.
- Therefore, the primary function of a telescope is to magnify objects, especially celestial bodies like stars, planets, and galaxies.
Correct Option: A) Magnify objects
Incorrect Options
- B) Study sound waves — Telescopes are optical instruments that deal with electromagnetic radiation (light), not sound waves. Instruments like hydrophones or sonar are used to study sound waves.
- C) Measure temperature — While some specialized astronomical instruments might infer temperature from light properties, the primary function of a standard telescope is not to measure temperature directly. Thermometers or pyrometers are used for temperature measurement.
- D) Analyze DNA — Analyzing DNA is a function of biological and genetic research, typically performed using microscopes, centrifuges, and other laboratory equipment, not telescopes.
3.
Which type of telescope uses lenses to gather and focus light?
ANSWER :
B. Refracting telescope
Approach
The question asks to identify the type of telescope that uses lenses to gather and focus light. We need to recall the basic principles of different telescope types.
Step-by-step
- Understand the function of a telescope: A telescope is an optical instrument designed to make distant objects appear nearer, containing an arrangement of lenses or curved mirrors, or both, by which rays of light are collected and focused to form a magnified image.
- Analyze the term "lenses": Lenses work on the principle of refraction, bending light as it passes through them to bring it to a focus.
- Recall types of telescopes:
- Refracting telescopes: These telescopes use lenses to gather and focus light. The primary optical element is a large objective lens.
- Reflecting telescopes: These telescopes use mirrors to gather and focus light. The primary optical element is a large concave mirror.
- Radiotelescopes: These detect radio waves, not visible light, and typically use large dish antennas.
- X-ray telescopes: These detect X-rays, which are high-energy electromagnetic radiation, and use specialized grazing incidence mirrors, not conventional lenses.
- Match the description: The description "uses lenses to gather and focus light" directly matches the definition of a refracting telescope.
Correct Option: B) Refracting telescope uses lenses (an objective lens and an eyepiece lens) to gather and focus light, bending the light rays through refraction.
Incorrect Options
- A) Reflecting telescope — This type of telescope uses mirrors (typically a concave primary mirror) to gather and focus light, not lenses.
- C) Radiotelescope — This instrument detects radio waves, a different part of the electromagnetic spectrum, and uses large dish antennas to collect these waves, not optical lenses.
- D) X-ray telescope — This type of telescope detects X-rays and uses specialized mirrors (grazing incidence mirrors) because X-rays would pass through conventional lenses or reflect off mirrors at normal incidence. It does not use lenses to gather and focus light in the traditional sense.
4.
Which telescope is located in space?
A.
Hubble Space Telescope
ANSWER :
A. Hubble Space Telescope
Approach
The question asks to identify which of the given telescopes is located in space. This requires knowledge of the location (ground-based or space-based) of prominent observatories and telescopes.
Step-by-step
- Evaluate each option to determine its location.
- The Hubble Space Telescope is well-known for being a space-based observatory.
- The Keck Observatory, Arecibo Telescope, and Very Large Telescope are all prominent ground-based observatories.
- Based on this, the Hubble Space Telescope is the correct answer.
Correct Option: A) The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It is one of the largest and most versatile telescopes, known for its significant contributions to astronomy and astrophysics.
Incorrect Options
- B) Keck Observatory — The Keck Observatory consists of two large optical/infrared telescopes located near the summit of Mauna Kea in Hawaii, USA. It is a ground-based observatory.
- C) Arecibo Telescope — The Arecibo Telescope was a radio telescope located in the municipality of Arecibo, Puerto Rico. It was a ground-based facility, famous for its large spherical reflector dish. Unfortunately, it collapsed in 2020.
- D) Very Large Telescope — The Very Large Telescope (VLT) is a facility operated by the European Southern Observatory (ESO) on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes and is a ground-based observatory.
5.
What is the main part of a reflecting telescope?
ANSWER :
B. Concave mirror
Approach
The question asks to identify the main optical component of a reflecting telescope. We need to recall the basic construction and working principle of reflecting telescopes.
Step-by-step
- Reflecting telescopes, as their name suggests, use mirrors to gather and focus light.
- The primary component responsible for collecting light from distant objects and forming an initial image is a large mirror.
- This mirror needs to converge the incoming parallel rays of light to a focal point. A concave mirror has the property of converging parallel rays of light.
- Therefore, a large concave mirror is the main light-gathering and focusing element in a reflecting telescope.
Correct Option:
B) Concave mirror — A reflecting telescope uses a large concave mirror as its primary objective to collect and focus light from distant celestial objects. This mirror reflects the light to a focal point, where it is then magnified by an eyepiece.
Incorrect Options
- A) Convex lens — Convex lenses are used in refracting telescopes as the objective lens. Reflecting telescopes, however, use mirrors to avoid chromatic aberration and to build larger apertures.
- C) Prism — Prisms are typically used to disperse light into its constituent colors (like in a spectrometer) or to reflect light through total internal reflection (like in binoculars or periscopes). They are not the primary light-gathering element in a telescope.
- D) Liquid crystal — Liquid crystals are used in displays (LCDs) and other electronic devices to modulate light. They have no role as the primary light-gathering or focusing element in traditional telescopes.
6.
What type of waves do radio telescopes detect?
Approach
The question asks about the type of electromagnetic waves that radio telescopes are designed to detect. Understanding the name and function of a specific type of telescope is key to answering this question.
Step-by-step
- Identify the instrument: The instrument mentioned is a "radio telescope."
- Relate instrument name to function: The name of a telescope often indicates the type of electromagnetic radiation it is designed to observe. For example, an optical telescope observes visible light, an X-ray telescope observes X-rays, and so on.
- Apply to radio telescope: Following this pattern, a radio telescope is specifically built to detect radio waves. These waves are part of the electromagnetic spectrum and have the longest wavelengths and lowest frequencies.
- Confirm with astronomical observation: Radio telescopes are used to study celestial objects that emit radio waves, such as pulsars, quasars, and the cosmic microwave background radiation.
Correct Option: C) Radio waves. Radio telescopes are specifically designed to detect and analyze radio waves emitted by celestial objects. Their large dish antennas collect these long-wavelength electromagnetic waves, which are then processed to create images and spectra of distant cosmic sources.
Incorrect Options
- A) Infrared waves — Infrared telescopes are used to detect infrared radiation, which has a longer wavelength than visible light but shorter than radio waves.
- B) Gamma rays — Gamma-ray telescopes are used to detect gamma rays, which are the most energetic form of electromagnetic radiation with the shortest wavelengths.
- D) X-rays — X-ray telescopes are used to detect X-rays, which are high-energy electromagnetic waves with wavelengths shorter than UV light but longer than gamma rays.
